Marvair® Reverse Cycle Air Conditioners

Self-Contained and Split System

Reverse Cycle Air Conditioners

Self-Contained Models MAB 07-10-12-16-24 and

Split System Models CA (Compressor Section) & DEMH (Evaporator Section)

Owner’s and Installation Manual

Self-Contained Unit

Chapter 1:
Safety Considerations............................................................................2
Chapter 2:
Model Identification...............................................................................3
Chapter 3:
Routine Maintenance.............................................................................4
Chapter 4:
Installation Instructions.........................................................................7
Chapter 5:
Thermostats and Controllers................................................................ 21
5.1 o-Touch Thermostat/Controller....................................................... 21
5.2 o-LED Thermostat/Controller.......................................................... 31
5.3 MachAir I Thermostat Controller..................................................... 39
Chapter 6: Start-Up............................................................................................. 56
Chapter 7: Winterizing the System........................................................................ 57
Chapter 8: Troubleshooting.................................................................................. 58
Chapter 9: Warranty............................................................................................ 62
Appendix A: Dimensional Drawings......................................................................... 64
Appendix B: Wiring Diagrams................................................................................. 66

Manufactured by:

Marvair Division of AIRXCEL™, Inc

®
Marvair Marine UK
®

PO Box 400 • Cordele, GA 31010 Unit 6 Benridge Park • Holyrood Close

156 Seedling Dr. • Cordele, GA 31015 Poole, Dorset BH17 7BD
(229) 273-3636 • Fax (229) 273-5154 +44 1202 606405
Email: marvair@airxcel.com www.marvair.co.uk
www.marvair.com/marine
Marvair® Self-Contained and Split Systems Installation & Owner’s Manual 1/2011 Part #01751,
Page1/2011
1 of 68
 Marvair® Reverse Cycle Air Conditioners
Chapter 1 – Safety Considerations
Congratulations on your purchase of a Marvair® marine air conditioner. Your air conditioner has been
designed to provide years of safe, dependable operation. These instructions contain a general description on
the operation of the unit, how to set up or program the thermostat/ controller, a list of routine maintenance
items, basic trouble shooting information, and the warranty.
The first thing we recommend for you to do is to write down the model number and the serial number of
the unit. Both numbers can be found on the data label on the unit. Refer to them whenever you call upon
your Marvair® dealer regarding this unit.
Model No. _________________________________ Serial Number___________________

Safety Considerations
This is the safety alert symbol . When you see this symbol on the Marvair® unit and in the instruction
manuals be alert to the potential for personal injury. Understand the signal word DANGER, WARNING
and CAUTION. These words are used to identify levels of the seriousness of the hazard.
DANGER Failure to comply will result in death or severe personal injury and/or property damage.

WARNING Failure to comply could result in death or severe personal injury and/or property damage.

CAUTION Failure to comply could result in minor personal injury and/or property damage.
IMPORTANT is used to point out helpful suggestions that will result in improved installation, reliability
or operation.

DANGER
Self-contained units or evaporators of split systems should never be installed in engine rooms or other
areas where fuel, battery or bilge vapors may be introduced to the living quarters on board.
These components do not meet federal requirements for ignition protection. Do not install in spaces
containing gasoline engines, tanks, LPG/CPG cylinders, valves, fuel line fittings, or regulators. Failure
to comply may result in injury or death. (Condensing units do comply with USCG/ABYC Ignition
Protection standards and may be installed in engine compartments.)
Do not terminate condensate drain line within four feet of any outlet of engine or generator exhaust
systems, nor in a compartment housing an engine or generator.
Installation and servicing of this system can be hazardous due to system pressure and electrical
components. When working on this equipment, always observe precautions described in the literature,
tags and labels attached to the unit(s). Follow all safety codes.
Marvair recommends that you use only factory certified, EPA licensed refrigerant technicians and
qualified marine electricians. ABYC certification in both HVAC and Marine electrical trades is
desirable. In receiving these certifications, a technician and his employer has made a statement of
commitment to professional, technically proficient and reliable service.

CAUTION
Under both heating and cooling modes of operation, certain components will run at fairly high
temperatures. Exercise care in working around operating equipment. Do not touch operating
machinery without the aid of qualified personnel, as referred to above.
Marvair® Self-Contained and Split Systems Installation & Owner’s Manual 1/2011 Page 2 of 68
 Marvair® Reverse Cycle Air Conditioners
Standards & Codes
Various codes & standards published by organizations are referenced in this manual. Some of the
organizations may be contacted in order to obtain complete copies of the code or standard.
American Boat & Yacht Council (ABYC)
613 Third Street, Suite 10
Annapolis, MD 21403
PH. (410) 990-4460
www.abycinc.org.

National Electric Code

National Fire Protection Association
1 Battery March Park
PO Box 9101
Quincy, MA 02269-9904

CE Directives

Chapter 2 - Model Identification

The Marvair® line of reverse cycle air conditioners built by Marvair® are self-contained and split systems,
water-cooled units designed for use with either fresh or seawater. The units are built in various sizes with
capacities from 7,000 to 24,000 BTUH. Both 115 volt and 230 volt models are available. The units are
designed to be controlled with a thermostat/ controller. Please refer to the model number designator to
determine the exact specifications for your unit.

Model Identification - Self-Contained Units

M A B •• •• • ••

M = Marine Refrigerant Controller Nominal Capacity System Type Voltage

A = R-410A B = Electronic 07 = 7,000 BTUH AC = Air A = 208/230V, 1ø, 60 Hz
Control Board 10 = 10,000 BTUH Conditioner B = 115V, 1ø, 60 Hz
12 = 12,000 BTUH RC = Reverse W= 220/240V, 1ø, 50 Hz Electronic Thermostat/
16 = 16,000 BTUH Cycle Controller
24 = 24,000 BTUH M2 = o-LED or
o-Touch Board

Model Identification - Split System Condensing Section

C A B •• •• • ••

Marine Refrigerant Controller Nominal Capacity System Type Voltage

A = R-410A B = Control 07 = 7,000 BTUH AC = Air Conditioner A = 208/230V, 1ø, 60 Hz
Board 10 = 10,000 BTUH RC = Reverse Cycle B = 115V, 1ø, 60 Hz Electronic Thermostat/
12 = 12,000 BTUH W= 220/240V, 1ø, 50 Hz Controller
16 = 16,000 BTUH M2 = o-LED or
24 = 24,000 BTUH o-Touch Board

Marvair® Self-Contained and Split Systems Installation & Owner’s Manual 1/2011 Page 3 of 68
 Marvair® Reverse Cycle Air Conditioners
Model Identification - Split System Air Handler Section
DEMH ••
•• •
Direct Expansion Nominal Capacity
Air Handler 07 = 7,000 BTUH System Type Voltage
10 = 10,000 BTUH AC = Air Conditioner A = 208/230V, 1ø, 60 Hz
12 = 12,000 BTUH RC = Reverse Cycle B = 115V, 1ø, 60 Hz
16 = 16,000 BTUH W= 220/240V, 1ø, 50 Hz
24 = 24,000 BTUH

Operating Ranges
The Marvair® reverse cycle air conditioner is designed to operate over a wide variety of conditions. Among
the most important factors that affect the performance of the unit are inlet water temperature, (return) inlet
air temperature and the humidity of the inlet (return) air. Please consult your Marvair® Marine dealer or
the factory if you have a question about the operation of your unit.

Chapter 3 - Routine Maintenance

Return Air Filters
Return air filters should be cleaned regularly. The filter shipped with your Marvair® unit is located in front
of the air coil.

Figure 1. Filter can be cleaned with a vacuum cleaner.

Condensate Pan and Lines

The condensate line can develop an algae type growth. Periodic inspection and treatment with a mild
solution of bleach and water poured into the condensate pan will keep the condensate pan and lines clear.
In split systems, the condensate pan is in the air handler.

Sea Water Strainer

The seawater strainer is available in several configurations – bronze or plastic. Yours has been sized in
accordance to system specifications for volume of water required. It is used to prevent debris such as
eelgrass, sea weed, leaves, etc., from passing through the system water lines and condensing coil. These
items could lodge themselves in the water supply causing possible shutdown faults, and left unchecked,
equipment damage. Should the strainer become clogged or partially obstructed, adverse performance will
be experienced. The first indication will be a high pressure switch activation if the unit is in the cooling
mode or low pressure if the unit is in the heating mode. The unit will shut down. Turn unit off; check

Marvair® Self-Contained and Split Systems Installation & Owner’s Manual 1/2011 Page 4 of 68
 Marvair® Reverse Cycle Air Conditioners
strainer and pump, restart. (See Sea Water Pump and Troubleshooting.)

Figure 2a. Unscrew and remove Figure 2b. Remove dirty Screen Figure 2c. Rinse Screen with clean
Screen Housing water. Reinstallation is the reverse
of removal
To eliminate these potential problems, it is recommended that you check to make sure you have water
flow each time you turn the system on and clean your strainer weekly. More often as conditions dictate.
Localized situations: In some regions, it is common to experience a tremendous presence of jellyfish or
sea nettles concentrated in back bay marinas for short periods of time. These can clog strainers and water
pumps every hour to hour and a half in some cases. In such severe conditions, seek the advice of your local
factory service representative. They will be most familiar with solutions to localized situations. Marvair
works closely with our servicing dealers when custom solutions are required. During the warranty period,
factory approval must be obtained for any modification to be done to alleviate the problem.

Sea Water Pump Operation and Maintenance

Your seawater pump has been sized in accordance with specifications for system water flow and volume.
While it will shut down to protect from damage, it is not advisable to run the seawater pump dry. Possible
damage may still be incurred. Damage incurred due to a pump running dry is not covered under warranty.
The pump is not self-priming. It must be initially primed upon commissioning. Properly installed, once
primed, barring haul outs or interrupted water flow due to an external cause, it should not need to be
primed again.
Occasionally, sea grass, jellyfish and other items may pass through your strainer and get lodged in the
pump impeller. Should cleaning your strainer fail to eliminate a water flow problem, you should next
contact your Marvair® Marine air conditioner service technician.
Units that have the thermostat may have the optional pump sentry monitor. Please see page 16 for a
description of the pump sentry.
Minimum Water Flow* for Marvair® Reverse Cycle Self-Contained Systems
Model (BTUH) Minimum Water Flow at the Unit
7,000 2.0 GPM / 7.6 LPM
10,000 2.9 GPM / 11.0 LPM
12,000 3.5 GPM / 13.3 LPM
16,000 4.7 GPM / 17.8 LPM
24,000 7.0 GPM / 26.5 LPM
*
Based upon 85°F (29.5°C) inlet water measured at the inlet of the unit.
Table 1. Minimum Water Flow Chart

Marvair® Self-Contained and Split Systems Installation & Owner’s Manual 1/2011 Page 5 of 68
 Marvair® Reverse Cycle Air Conditioners
Grilles and Proper Air Flow
The MAB series of units features the Marvair Box blower. The box blower, with its backward inclined
impeller, moves air through duct with a minimum of noise. Air outlets on the top and on each side facilitate
the connection of duct and can eliminate the use of a “Y” or “T” transition.
Adequate air flow is essential for the proper operation of the air conditioner. All grilles, both supply and
return air, must never be restricted by objects such as bed linens, duffel bags, tackle bags, etc. Your unit
has been designed to deliver conditioned air over a wide range of conditions. However, a dirty filter, or
restricted ductwork can prevent proper air flow. If this situation exists and the unit is in cooling mode, ice
may form on the coil and the unit will go into the defrost mode.
The unit may go into the Defrost mode or the HPS alarm to be displayed occasionally. However, repeated
Defrost cycles or High Pressure notices indicate a problem and you should contact your Marvair® Marine
dealer or the factory. If you have the MachAir I controller, no indication is made on the display when the
unit enters the Defrost Mode.
If you have the o-LED or o-Touch thermostat controller, when a high refrigerant pressure is detected, High
Refrigerant Pressure is shown on the screen of the thermostat.

Return Air Grille(s) and Filter(s)

Return air grilles are available in both aluminum and wood in standard configurations. They do not have
adjustable louvers and are available with and without filters. Return air filters should be cleaned regularly.
The filter shipped with your unit is located in front of the air coil and can be cleaned with a vacuum cleaner
or rinsed with fresh water.
If your unit’s return air grille has a filter, be sure that your boat builder or installation technician has
removed the standard filter that comes with every unit in front of the evaporator (air) coil. Two filters can
unduly restrict air flow and in some cases, cause problems with performance. Use EITHER a return air
filter grille or the supplied filter, never both.
Depending upon the floor plan, your boat’s space constraints may dictate that a unit be installed in an area
that makes it difficult to access and clean the filter. If this is the case, and you do not have a return air filter
grille, you should consider removing the disposable unit filter and upgrading to a return air filter grille.
NOTE: Blocking the return air grille or neglecting filter cleaning will result in a restriction of air flow.
In the heating mode, this will cause a HIGH PRESSURE FAULT shutdown. In the cooling mode, after a
period of time, you will experience icing of the evaporator coil and a resultant LOW PRESSURE FAULT
shutdown or activation of the defrost sensor.

Supply Air Grille(s)

Most installations will have more than one supply air grille. Standard main supply air grilles are generally
made of aluminum or wood frames with two or four-way adjustable louvers. These may be adjusted to
direct air flow from the grille to ensure a uniform cabin temperature. Main supply air grilles should never
be closed at any time while running in either the heating or cooling modes. Secondary supply air grilles
more frequently will be a 4” round plastic design, but they can also be of the aluminum or wood frame
standard configuration and are usually located out of the main salon, galley, dinette area. These may,
depending upon the style you or your boat manufacturer has chosen, be closable. During the day, these
may be closed should you like more air directed to the main living area. Consult with your local Marvair®
Marine service representative if you are unsure which are the main supply grilles on your boat. Closing

Marvair® Self-Contained and Split Systems Installation & Owner’s Manual 1/2011 Page 6 of 68
 Marvair® Reverse Cycle Air Conditioners
off the main supply air grille or secondary air grilles, in some applications, may restrict air flow in the
cooling mode, cause ice to form on the evaporator coil and a low pressure fault shut down. If the unit is in
the heating mode, inadequate air flow can cause a high pressure fault shut down.
Should either of these conditions occur, open all closed supply air grilles and restart system. This
should eliminate the problem. If the problem recurs again, consult your local Marvair Marine service
representative.

Chapter 4 - Installation Instructions

General Operation
The Marvair® reverse cycle air conditioner has both a heating and cooling mode of operation.

It uses refrigerant in a conventional vapor compression cycle to transfer heat from the air in the boat to
the water. In the cooling mode, a blower blows the cabin air through the indoor or evaporator coil where
it is cooled and dehumidified. Liquid refrigerant passing through the evaporator is boiled into a gas by
heat removed from the air. The warmed refrigerant gas enters the compressor where its temperature and
pressure are increased. The hot refrigerant gas travels to the water coil or condenser where it is cooled by
the water and condenses to a liquid. Liquid refrigerant is metered back into the evaporator coil to repeat
the process.
In the heating mode, the process is reversed. A special reversing valve reverses the flow of the refrigerant
throughout the system exchanging the roles of the condenser and evaporator. The refrigerant flows through
the water or evaporator coil, picks up heat from the water, and becomes a vapor. The vapor then enters
the compressor where it is compressed to a higher temperature. It is then pumped to the indoor coil where
the air moving across the coil picks up the heat and the warm air is blown into the room. The compressed
refrigerant vapor condenses to a liquid as it gives up heat. Finally, liquid refrigerant flows into the capillary
tubes into the indoor coil where the cycle is repeated.
The reverse cycle air conditioner is controlled by a thermostat mounted on the wall.
In the self-contained units, all the components are in a single package. In a split system, the compressor
and the water coil are one unit, called the compressor section, and the air coil and the blower are in another,
called the evaporator or blower section. Field installed copper refrigerant lines and control wiring connect
the two units. Cooling and heating performance of the two units is virtually identical.

A. High Pressure Switch

Located on the liquid refrigerant line, it is electrically connected to a lock-out relay which shuts the unit
off if the refrigerant pressure rises above the pressure set point. See chart below for pressure set points of
the various refrigerants. This protects the reverse cycle air conditioner if air flow is reduced or water flow
is restricted.

The contacts on the high pressure switch close when the refrigerant pressure falls below the pressure set
point. See chart below for pressure set points of R-410A refrigerant. The system must be checked for
sufficient water flow in the cooling mode and air flow in the heating mode. See Section Fail Safe & Fault
Handling Modes in the thermostat/controller section.

Marvair® Self-Contained and Split Systems Installation & Owner’s Manual 1/2011 Page 7 of 68
 Marvair® Reverse Cycle Air Conditioners
B. Low Pressure Switch
Located on the liquid refrigerant line, it is electrically connected to a lock-out relay which shuts the
system off if the refrigerant pressure drops below the pressure set point. See chart on following page for
pressure set points of the various refrigerants This protects the reverse cycle air conditioner if air flow is
reduced in the cooling mode or water flow is restricted in the heating mode or there is a substantial loss
of refrigerant.

The contacts on the low pressure switch close when the refrigerant pressure rises above the pressure set
point. See chart below for pressure set points of the various refrigerants. See Section Fail Safe & Fault
Handling Modes in the thermostat/controller section.

R-410A Refrigerant
Opens Closes
Low Pressure 40 psig 60 psig
High Pressure 610 psig 420 psig
Table 2. Refrigerant Pressure Points

C. Compressor Time Delay

Prevents compressor from destructive short cycling by delaying the compressor from starting when
compressor contactor is energized. The delay is set at the factory from 10-15 seconds.

Sizing the Air Conditioner

Room “K” Factor (USA) K” Factor (Metric)
Below decks with conditioned areas above and on three sides 7 250
Below decks with conditioned areas above and on two sides 12 425
Below decks 14 495
Galley 17 600
Above decks with large window areas 19 670
Above decks with large window areas and heavy outdoor traffic 21 740
Bridge or pilot house, all windows and heavy traffic 24 850
Table 3. Air Conditioner Size Calculation

Calculation of BTU Load:

•• Determine cubic feet or meters by multiplying height by width by length of area to be cooled.
•• Determine BTUs by multiplying cubic feet or cubic meters by the “k” factor.
USA Example: Room is below deck with conditioned areas above and on three sides. Room dimensions
are 7ft. high by 12 ft. wide by 15 ft. long

1. 1,260 ft3 (7x12x15)

2. 1,260 ft3 x 7 (k factor) = 8,820 BTU
Based upon a load of 8,820 BTUH, a 10,000 BTUH unit would be required.

Marvair® Self-Contained and Split Systems Installation & Owner’s Manual 1/2011 Page 8 of 68
 Marvair® Reverse Cycle Air Conditioners
Metric Example: Room is below deck with conditioned areas above and three sides. Room dimensions
are 213 cm high by 366 cm wide by 457cm long.

1. 35.63m3 (213x366x457)
2. 35.63m3 x 250 (k factor) = 8,908 BTU
Based upon a load of 8,908 BTUH, a 10,000 BTUH unit would be required.

Equipment Inspection
Concealed Damage
Inspect all cartons and packages upon receipt for damage during transit. Remove shipping cartons and
boxes and check for concealed damage. Important: Keep unit upright at all times.

Inspect refrigerant circuit for fractures or breaks. The presence of refrigerant oil usually indicates a rupture
in the refrigerant circuit.

Units that have been turned on their sides or upside down may have concealed damage to the compressor,
other components or to the refrigerant system. If the unit is not upright when you receive it, immediately
file a claim with the freight carrier for concealed damage and follow these steps:

1. Set unit upright and allow to stand for 24 hours with primary power turned OFF.
2. After 24 hours, connect power to unit.
3. Attempt to start the unit after 24 hours.
4. If the unit will not start or makes excessive noise, return the unit to the freight carrier.

Installation Requirements
WARNING
If the information in these instructions is not followed exactly, a fire, carbon monoxide poisoning or
explosion may result causing property damage, personal injury or loss of life • Read all instructions
carefully prior to beginning the installation. Do not begin installation if you do not understand any of the
instructions. • Improper installation, adjustment, alteration, service or maintenance can cause property
damage, personal injury or loss of life. • Installation and service must be performed by a qualified
installer, service agency in accordance with these instructions and in compliance with all codes and
requirements of authorities having jurisdiction.

A. Location Requirements
•• Do not install the Marvair® reverse cycle air conditioner in an engine room, the bilge or any areas
where it may introduce deadly or noxious vapors into the boat’s living space. Do not install the unit
in any room or compartment that contains an internal combustion engine. Note: The compressor
section of the split systems are ignition protected and may be located in an engine room. However,
do not install the blower section in areas containing internal combustion engines, fuel tanks, LPG/
CPG cylinders, regulators, valves or fuel line fittings.
•• The condensate drain line must not terminate within three (3) feet of the exhaust of any engine or
generator nor any room that contains an engine or generator. Under some circumstances, carbon
monoxide can be pulled through the condensate tubing and introduced into the conditioned air.

Marvair® Self-Contained and Split Systems Installation & Owner’s Manual 1/2011 Page 9 of 68
 Marvair® Reverse Cycle Air Conditioners
•• It is recommended not to install the reverse cycle air conditioner above an electronic or electrical
panel, circuit breakers or anything electrical. If installed in this or an overhead location, a secondary
drain pan should be used.
•• Select a location for noise considerations. Putting the unit under a bunk may not be desirable for
sound reasons. A better location may be at the bottom of a hanging locker. In some installations,
acoustic baffles may be required.
•• The Marvair ® self-contained reverse cycle air conditioners do NOT meet Federal requirements
for ignition protection. Never install the unit in areas containing internal combustion engines, fuel
tanks, LPG/CPG cylinders, regulators, valves or fuel line fittings. Note: The compressor section
of the split systems are ignition protected and may be located in an engine room. However, do not
install the blower section in areas containing internal combustion engines, fuel tanks, LPG/CPG
cylinders, regulators, valves or fuel line fittings.
•• The unit must be installed in a space with sufficient clearance on all sides for proper air circulation
and for services. A minimum of three (3) inches must be provided from the face of the air coil
to any obstruction, wall or bulkhead. Sufficient air flow is critical to the proper operation of the
unit.
•• Before placing the unit(s) into the space, make certain that there is sufficient room for all duct
work, condensate line connections, water in and out, electrical power connections and control
power connections.
•• The unit must be installed on level surface on a minimum of ½” plywood or equivalent. The
condensate line must, at all times, be lower than the base pan.
•• For optimum air circulation, it is good practice to install the supply air grilles near the top of
the cabin and the return air grille near the floor. This normally provides good circulation of the
conditioned air throughout the cabin. The location should provide easy access to the filter. If the
filter is not readily accessible, it probably will not be changed, shortening the life of the unit and
operating at less than designed performance.
•• To save space & facilitate installation, the Marvair reverse cycle air conditioner has a detachable
electrical box. The box can be mounted on the unit’s water connection side, the return air side,
above the compressor or remote from the unit.

Electrical Requirements
WARNING ELECTRIC SHOCK HAZARD
Failure to follow safety warnings exactly could result in serious injury, death, and/or property damage.
Turn off electrical power at fuse box or service panel BEFORE making any electrical connections and
ensure a proper ground connection is made before connecting line voltage.

All electrical work must meet the requirements of all applicable codes and ordinances. Work should only
be done by qualified persons.

If the wiring diagram that is on or was shipped with the unit is different from the one in this manual, refer
to and use the wiring diagram that is on or was shipped with the unit.

Marvair® Self-Contained and Split Systems Installation & Owner’s Manual 1/2011 Page 10 of 68
 Marvair® Reverse Cycle Air Conditioners
1. High Voltage Wiring (115V or 230V) The power supply must have the proper voltage, phase and
ampacity for the selected model.
a. Refer to the data label on the unit for field wiring requirements. The electrical data lists fuse
and wire sizes for the unit.
b. Each unit has a Minimum Circuit Ampacity (MCA). Field wiring must be used that is of
sufficient size to carry that amount of current. Use copper conductors only. Refer to the National
Electrical Code for complete current carrying capacity data on the various insulation grades of
wiring materials.
c. Power supply must be within allowable range of ±10% of rated voltage.
d. The unit must be properly grounded to reduce the risk of shock or electrocution.
e. A properly sized circuit breaker must be used. Information required to size the breaker is on
the unit. The water pump does not require a separate breaker if there is only one reverse cycle
air conditioner. However, the breaker must be sized for both the water pump and the Marvair®
unit. A separate breaker is required for the water pump if multiple Marvair units are installed.
f. Connections between the ship’s alternating current grounding conductor and the ship’s negative
or bonding system must be made as part of the ship’s wiring as per ABYC standard E-11 or
equivalent.
g. When servicing or replacing existing equipment that contains a chassis mounted ground lug, the
service person or installed must verify the ship’s wiring for the connection required in item f.
above.
h. All electrical connections must be made within the electrical junction boxes supplied with the
unit. A terminal strip and/or electrical connectors are provided for component installation.

Electrical Data for Self-Contained Units - Models MAB

Performance & Electrical Data for MAB self-contained units, 208-230v, 60 Hz.
Nominal Unit Run Amps
MODEL
Capacity Volts / Ph / Hz LRA KVA1 2
MCA5 MFS6
NUMBER Cooling 3
Heating 4
(BTUH)
MAB07RCA 7,000 208-230/1/60 22.2 0.9 2.97 3.84 5.1 10
MAB10RCA 10,000 208-230/1/60 22.2 1.0 3.34 4.49 5.9 10
MAB12RCA 12,000 208-230/1/60 32.5 1.2 3.89 5.01 6.8 10
MAB16RCA 16,000 208-230/1/60 29.0 1.4 4.58 6.05 8.3 10
MAB24RCA 24,000 208-230/1/60 58.3 2.3 6.96 9.96 17.7 25
1
LRA = Locked Rotor amps (compressor only) 2
KVA = Kilovolt amps
3
Cool = 45°F evaporator and 100°F condenser 4
Heat = 45°F evaporator and 130°F condenser.
5
MCA = Minimum Circuit Ampacity (Wire size amps) 6
MFS = Maximum Fuse or HACR breaker size
Table 4a. Performance & Electrical Data for 208-230v Units

Marvair® Self-Contained and Split Systems Installation & Owner’s Manual 1/2011 Page 11 of 68
 Marvair® Reverse Cycle Air Conditioners
Performance & Electrical Data for MAB self-contained units, 115v, 60 Hz.
Nominal Unit Run Amps
MODEL
Capacity Volts / Ph / Hz LRA KVA1 2
MCA5 MFS6
NUMBER Cooling3 Heating4
(BTUH)
MAB07RCB 7,000 115/1/60 45.6 0.91 6.26 7.95 10.4 15
MAB10RCB 10,000 115/1/60 45.6 1.07 7.01 9.27 12.0 20
MAB12RCB 12,000 115/1/60 63.0 1.24 8.60 10.80 13.3 20
MAB16RCB 16,000 115/1/60 63.0 1.62 11.50 14.09 14.6 20
1
LRA = Locked Rotor amps (compressor only) 2
KVA = Kilovolt amps
3
Cool = 45°F evaporator and 100°F condenser 4
Heat = 45°F evaporator and 130°F condenser.
5
MCA = Minimum Circuit Ampacity (Wire size amps) 6
MFS = Maximum Fuse or HACR breaker size
Table 4b. Performance & Electrical Data - 115v Units

Performance & Electrical Data for MAB self-contained units, 220-240v. 50 Hz.
Nominal Unit Run Amps
MODEL
Capacity Volts / Ph / Hz LRA1 KVA2 MCA5 MFS6
NUMBER Cooling3 Heating4
(BTUH)
MAB07RCW 7,000 220-240/1/50 18.8 0.9 2.80 3.74 5.2 10
MAB10RCW 10,000 220-240/1/50 21.0 1.0 3.20 4.22 5.2 10
MAB12RCW 12,000 220-240/1/50 21.0 1.0 3.20 4.22 5.2 10
MAB16RCW 16,000 220-240/1/50 24.5 1.4 4.39 5.89 6.4 10
MAB24RCW 24,000 220-240/1/50 61.0 2.8 8.26 11.86 16.5 25
1
LRA = Locked Rotor amps (compressor only) 2
KVA = Kilovolt amps
3
Cool = 45°F evaporator and 100°F condenser 4
Heat = 45°F evaporator and 130°F condenser.
5
MCA = Minimum Circuit Ampacity (Wire size amps) 6
MFS = Maximum Fuse or HACR breaker size
Table 4c. Performance & Electrical Data - 220-240v Units

2. Bonding. To prevent corrosion due to stray electrical current or voltage, all metallic parts in contact
with water must be connected to the ship’s bonding system. This includes the reverse cycle air
conditioner, all pumps, metallic valves, fittings, strainers and thru-hulls. If any of these parts are
isolated by PVC, vinyl, or rubber hoses, they must be individually bonded to the ship’s bonding
system. Failure to properly ground and bond the system will void the warranty.

Mounting of the Marvair® Reverse Cycle Air Conditioner

Select a surface that is firm and level, with sufficient clearances. Mount the unit on a minimum of ½”
plywood or equivalent. The unit will be secured to the surface with four hold down brackets. Secure the
bracket with suitable fasteners; e.g., lag screws. Note: To facilitate installation, the hold down fasteners
may be installed after all duct, water, condensate, and electrical connections are made.

Condensate Drains
(Applies to all self-contained units and the air handler section of all split units.)
WARNING CARBON MONOXIDE POISONING HAZARD
Failure to follow safety warnings could result in serious injury, death, or property damage.
The stainless steel base pan has multiple openings for condensate drains. It is highly recommended that
Marvair® Self-Contained and Split Systems Installation & Owner’s Manual 1/2011 Page 12 of 68
 Marvair® Reverse Cycle Air Conditioners
two of the openings be utilized – one for back-up in case the other one becomes clogged or blocked. The
other openings should be sealed and plugged. The reverse cycle air conditioner can produce significant
quantities of condensate that may cause extensive damage to the vessel if not disposed of properly.

A. Select the two openings that will NOT be used for condensate lines.
B. Plug and seal them.
C. Install the condensate drain fittings through the base pan. Make sure the fitting is water tight.
D. Attach a 5/8” ID reinforced hose to the hose barb and secure with two stainless steel hose clamps.
E. Route the condensate hose down from the Marvair reverse cycle air conditioner to a sump or to an
overboard fitting. If the drain runs overboard, it must not be within three (3) feet from the exhaust
from the engine or generator. Double clamp all connections.
F. If the condensate line is run through a room or compartment containing an engine or fossil fueled
device, it is imperative that the line be air tight to prevent carbon monoxide other any other
hazardous gases or vapors from being introduced into the conditioned air system.

Sea or Fresh Water System

Proper water flow is absolutely critical to the operation of the Marvair reverse cycle air conditioner. If
the pipe is too small, back pressure is created causing a drop in water flow, even if the pump is correctly
sized. If the piping is too large, the slow velocity of the water may cause silt build-up and barnacle growth
inside the piping, eventually restricting water flow. See Table 5, Recommended Pipe Sizes and Table 6,
Minimum Water Flow.

The best material for sea water piping and fittings is cupronickel. Suitable materials for piping are hi-grade
bronze cupronickel and schedule 80 PVC pipe. Materials to avoid are yellow brass, copper, poor grades
of aluminum, stainless steel or steel pipe. Use Teflon® tape or other appropriate sealant on all threaded
fittings to prevent leaks.

When using a centrifugal pump, the Marvair® reverse cycle air conditioner must be higher than the thru-
hull fitting, but lower than the heeled water line. The overboard fitting may be either higher or lower than
the unit. The tubing must never have any loops or kinks. If there is any place that water can be trapped,
damage may result during freezing temperatures. The pump and strainer must always be below the heeled
water line since centrifugal pumps cannot pump air. See Figure 4, Seawater Piping Schematics.

1. Thru-hull fitting. Install a scoop-type thru-hull fitting as close to the keel and as far below the
water line as possible to eliminate any possibility of air entering the system. Do not share the thru
-hull with any other device; i.e., an engine or generator. When using one thru-hull for multiple units,
the thru-hull must be sized for proper water flow.
The scoop-type thru-hull should face forward. On a fast planning board, locate the thru-hull at the
transom to ensure water flow.
2. Seacock. A bronze, full flow seacock or ball valve should be installed directly onto the thru-hull
fitting. The seacock must be closed to clean the strainer and in an emergency. Therefore, make it
easily accessible.
3. Strainer. The strainer must be installed so that it is always below the water line and below the
pump. It should be easily accessible for cleaning. Verify that the water flow is in the correct
direction. Secure the strainer to a bulk head.
Marvair® Self-Contained and Split Systems Installation & Owner’s Manual 1/2011 Page 13 of 68
 Marvair® Reverse Cycle Air Conditioners
4. Water Pump. Centrifugal pumps cannot pump air; i.e., they are not self-priming. Therefore, they
must be mounted so that they are below the heeled water line at all times. For service &
maintenance, the pump should be easily accessible. The PUMP pump should be installed with the outlet
HEAD ORIENTATION

pointed upward so that if air enters the system it can pass through the pump. The pump heads
on some pumps can be rotated to allow for mounting on a vertical surface. Self-priming pumps are
available if the pump cannot be installed below the water line.
CORRECT CORRECT
5. Manifolds. When a water pump supplies water to two or more Marvair units, a manifold with
balancing valves is required. It is mandatory when using a manifold that each unit have the
correct water flow. See Table 5 - Recommended Water Pipe Sizes. A manifold can also be used on
the discharge of the Marvair units if a single overboard fitting is used INCORRECT INCORRECT

PUMP HEAD ORIENTATION SEAWATER MANIFOLD ORIENTATION

Equal Flow More Flow

Less
Flow

More More More More

Flow Flow Flow Flow
CORRECT CORRECT Less Less Less Less
Flow Flow Flow Flow

INCORRECT INCORRECT
INCORRECT CORRECT

SEAWATER MANIFOLD ORIENTATION

Figure 3. Pump Head and Manifold Orientation
Equal Flow More Flow

6. Overboard Discharge. The overboard discharge should be no more than 2” above the water line. Less

This will minimize sound yet allow visual confirmation of water flow. If the overboard discharge
Flow

More More More More

Flow Flow Flow Flow
Less Less Less Less

fitting must be installed below the water line, a valve must be installed per ABYC standards.
Flow Flow Flow Flow

CORRECT INCORRECT
• Steady uphill flow from inlet to Marvair Marine unit. • Seawater pump must be below the waterline.
• Steady uphill or downhill flow from Marvair Marine unit to overboard.
• Hoses double clamped (with reversed clamps).
• Seawater
INCORRECTpump and strainer below waterline. CORRECT
A A

CW INLET
Seawater Outlet CW INLET
Seawater Outlet
Marvair Marine Unit
B
Marvair Marine Unit
B
1” F.P.T. FITTING 1” F.P.T. FITTING

Outlet Flow Outlet Flow

SW OUTLET SW OUTLET
5/8” ID HOSE 5/8” ID HOSE

C C
C E G C E G
CW OUTLET CW OUTLET
1” F.P.T. FITTING 1” F.P.T. FITTING

SW INLET SW INLET
H 5/8” ID HOSE H 5/8” ID HOSE

F F
D D

J
I L Waterline J
I L
K K
A A

Seawater Pump Seawater Pump

Inlet Flow Waterline

Strainer Strainer
Inlet Flow
Seacock (Ballvalve) Seacock (Ballvalve)
and scoop type and scoop type
through-hull inlet. through-hull inlet.

INCORRECT INCORRECT
• Hoses must not have kinks, loops, or high spots where air can • Strainer must be below the seawater pump and the waterline.
be trapped.

A A

CW INLET
Seawater Outlet CW INLET
Seawater Outlet
Marvair Marine Unit
B
Marvair Marine Unit
B
1” F.P.T. FITTING 1” F.P.T. FITTING

Outlet Flow Outlet Flow

SW OUTLET SW OUTLET
5/8” ID HOSE 5/8” ID HOSE

C C

Strainer
C E G C E G
CW OUTLET CW OUTLET
1” F.P.T. FITTING 1” F.P.T. FITTING

SW INLET SW INLET
H 5/8” ID HOSE H 5/8” ID HOSE

F F
D D

J
I L Waterline J
I L
K K
A A
Waterline
Seawater Pump Seawater Pump

Inlet Flow Inlet Flow

Strainer

Seacock (Ballvalve) Seacock (Ballvalve)

and scoop type and scoop type
through-hull inlet. through-hull inlet.

Figure 4. Seawater Piping Schematics

Marvair® Self-Contained and Split Systems Installation & Owner’s Manual 1/2011 Page 14 of 68
 Marvair® Reverse Cycle Air Conditioners
Recommended Water Pipe Sizes
Flow Rate (GPM) Pump Inlet Pipe Size Pump Discharge Pipe Size
1 through 4 5/8” 5/8”
4 through 7 3/4” 5/8”
7 through 11 1” 3/4”
11 through 15 1” 1”
15 through 20 1-1/4” 1”
Table 5. Recommended Water Pipe Sizes

Table 6 shows the minimum flow rate required, measured at the inlet to the unit, with 85°F (29.4°C)
water of the various units.

Minimum Water Flow* For Marvair Marine Self-Contained And Split Systems
Model (BTUH) Minimum Water flow at the unit
7,000 2.0 GPM/ 7.6 LPM
10,000 2.9 GPM / 11.0 LPM
12,000 3.5 GPM / 13.3 LPM
16,000 4.7 GPM / 17.8 LPM
24,000 7.0 GPM / 26.5 LPM
*Based upon 85°F (29.5°C) inlet water measured at the inlet of the unit.
Table 6. Minimum Water Flow Chart

Table 7 shows the pump capacity, with no head, of pumps from Cal Pumps and March Manufacturing.

March Pumps
Pump (GPH/LPH) 300/1,110 510/1,860 1,800/6,600
Max Ht (FT/M) 13/2.7 19/4.3 41/9.0

Cal Pumps
Pump (GPH/LPH) 375/1,421 860/3,259 1,200/4,160
Max Ht (FT/M) 12.7/3.87 14/4.27 18/5.50
Table 7. Pump Capacity, No Head

Marvair® Self-Contained and Split Systems Installation & Owner’s Manual 1/2011 Page 15 of 68
 Marvair® Reverse Cycle Air Conditioners
The Conditioned Air Duct & Grille System
WARNING CARBON MONOXIDE POISONING HAZARD
Failure to follow safety warnings could result in serious injury, death, or property damage. Do NOT
operate in a corrosive atmosphere containing chlorine, flourine or any other damaging chemicals which
could harm the unit and duct system, and permit spillage of combustion products into an occupied
space

Inadequate air flow is a leading cause of complaints and can significantly shorten the life of the unit,
The air distribution system must be engineered to ensure sufficient air flow throughout the system. This
included proper duct sizing and sufficient open area on the supply and return grilles
.

Figure 5. Typical Air System Installation Schematic

Marvair® Self-Contained and Split Systems Installation & Owner’s Manual 1/2011 Page 16 of 68
 Marvair® Reverse Cycle Air Conditioners
Duct work guidelines
• Duct work must be firmly attached, secured and sealed to prevent air leakage.
• Use transition boxes and/or plenums with duct to split and route the conditioned air as required.
• When using insulated flexible duct, make sure that the inner duct is secured and sealed to an
adapter before pulling the insulation over the connection
• Install the supply air grilles high on the cabin wall to create good air circulation. Stretch the duct
tight in straight runs.
• Make the bends and turns as large as possible. Secure the duct so that is remains in its
installed position.
• Always use insulated duct to prevent condensation.
• Insulate all transitions and plenums.
• If duct is in a storage or a high traffic area, protect it from being crushed by a shield or box.
• If the duct must be run through areas containing engines or fossil fueled devices, it is absolutely
mandatory that the duct system be air tight to prevent carbon monoxide and any other hazardous
gases or vapors from being introduced into the conditioned air system.

Return Air Grilles

The return air grille should be located to ensure unimpeded air flow to the air coil on the reverse cycle air
conditioner. The grille may be located on the opposite the coil provided there is a space around the unit for
sufficient air flow. Maintain at least 4” between the grille and the Marvair® unit. For good air distribution
throughout the cabin, the return grille should be located near the floor when the supply grilles are high on
the cabin wall. The return air grille must have sufficient open air to permit adequate air to the indoor coil.
The Marvair reverse cycle air conditioner has a factory provided filter located in front of the air coil. If a
return air filter grille is used, it is recommended that the filter on the unit be removed.

Supply Air Grille

The supply air grille must have sufficient open area to permit adequate air flow. To prevent short circuiting
of the conditioned air, adjust the vanes of the supply grille so that the discharge air is not directed to the
return air grille or to the thermostat/controller.

Marvair® Self-Contained and Split Systems Installation & Owner’s Manual 1/2011 Page 17 of 68
 Marvair® Reverse Cycle Air Conditioners
Minimum Minimum
Marvair P/N Qty of
Nominal Opening Opening for Minimum Outside Dimensions of
Model a of Blower Box Oval
Air Flowfor Return Supply Air Hose Size Hose Adapter
Number to Oval Hose Hose
Air Grille Grille(s)
Adapter Adapters
CFM m3/hr In2 cm2 In2 cm2 In cm Inches cm
200 340 5 12.7 HRF5b 2 6 x 2½ 15.2 x 6.4
MAB07RCA, RCB
225 382 7 17.8 HRF7 1 8¾ x 3-3/8 22.2 x 8.6
100 645 40 260
215 365 5 12.7 HRF5b 2 6 x 2½ 15.2 x 6.4
MAB07RCW
240 408 7 17.8 HRF7 1 8¾ x 3-3/8 22.2 x 8.6
215 365 6 15.2 HRF6b 2 7½ x 2¾ 19.1 x 7
MAB10RCA, RCB
215 365 7 17.8 HRF7 1 8¾ x 3-3/8 22.2 x 8.6
100 645 60 390
190 323 6 15.2 HRF6b 2 7½ x 2¾ 19.1 x 7
MAB10RCW
190 323 7 17.8 HRF7 1 8¾ x 3-3/8 22.2 x 8.6
325 552 6 15.2 HRF6b 2 7½ x 2¾ 19.1 x 7
MAB12RCA, RCB
310 527 7 17.8 HRF7 1 8¾ x 3-3/8 22.2 x 8.6
140 900 70 450
260 442 6 15.2 HRF6b 2 7½ x 2¾ 19.1 x 7
MAB12RCW
215 365 7 17.8 HRF7 1 8¾ x 3-3/8 22.2 x 8.6
320 544 7 17.8 HRF7b 2 8¾ x 3-3/8 22.2 x 8.6
MAB16RCA, RCB
305 518 8 20.3 HRF8 1 10 x 4 25.4 x 10.2
168 1110 84 540
275 467 7 17.8 HRF7b 2 8¾ x 3-3/8 22.2 x 8.6
MAB16RCW
290 493 8 20.3 HRF8 1 10 x 4 25.4 x 10.2
700 1189 8 20.3 HRF8b 2
MAB24RCA
525 892 8 20.3 HRF8 1
240 1550 192 1240 10 x 4 25.4 x 10.2
625 1062 8 20.3 HRF8b 2
MAB24RCW
465 790 8 20.3 HRF8 1
The blower box on all MAB units has openings for three duct adapters. For optimum performance and air flow, two duct
adapters should be used.
a
Use larger size hose if hose run is greater than 10 ft. (3 meters).
b
Two oval hose adapters are shipped with each MAB unit.
Table 8. Air Flow, Grille, and Duct Size
Air Flow Noise
Air moving through duct work and across the blades in the grilles and louvers generates sound. The faster
the air, the greater the sound. To keep sound to acceptable levels, the cross sectional area of the duct must
be large enough to keep the velocity below 600 ft/min (3m/sec). Air flow faster than this is likely to cause
noise complaints. The duct sizes in Table 8 are the minimum size required to deliver the proper air flow
without generating undue noise. Larger ducts will have less friction and less noise.

Electrical
WARNING ELECTRIC SHOCK HAZARD
Failure to follow safety warnings exactly could result in serious injury, death, and/or property damage.
Turn off electrical power at fuse box or service panel BEFORE making any electrical connections and
ensure a proper ground connection is made before connecting line voltage.

High Voltage
Prior to doing any work on the unit, turn the electrical power off at the breaker of fuse panel. Line voltage
is hazardous and can kill you. All electrical work must meet the requirements of all codes and ordinances.
Marvair® Self-Contained and Split Systems Installation & Owner’s Manual 1/2011 Page 18 of 68
 Marvair® Reverse Cycle Air Conditioners
All work should be done only by qualified persons. The power supply should have the proper voltage,
phase and ampacity for the selected model. Refer to the data label on the unit. Each Marvair® reverse cycle
air conditioner requires an appropriately sized, dedicated circuit breaker. If there is only one unit, the water
pump does not require a separate breaker, but the breaker must be sized for the combined load of the pump
and the unit. If multiple units are supplied by a single pump, a pump relay will be required and will require
a dedicated circuit breaker.

1. To facilitate installation, the Marvair® reverse cycle air conditioner has a detachable electrical
box and a heavy duty multi-wire cable harness. The box can be mounted on the unit’s water
connection side, the return air side, above the compressor or remote from the unit. Prior
to placing the unit in the desired location, mount the control box in the preferred position.
The electrical box can be mounted up to 5’ from the unit.
2. Size the incoming power supply conductors according to the code requirements. Run the power
conductors through the knockouts on the side of the electrical box. Use appropriate conduit and
strain relief.
3. Connect the conductors to the input side of the terminal block.
4. Install the ground wire on the ground lug.
5. The Marvair reverse cycle air conditioner has a solid state control board located in the electrical
box on the unit. This control board is compatible for use with either the o-Touch, o-LED, or the
MachAir I display/controller. The board is configured at the factory for the o-Touch and o-LED
display/controller. To use the board with the MachAir I display/controller, two pins must
be moved on the control board. The pins should be removed by hand; do not use pliers or a screw
driver to remove the pins.
1. Turn off the power to the Marvair unit at the breaker.
2. Remove the cover to the electrical box.
3. Carefully pull the two clips on JP11 & JP9 and move them to the position for use with the
MachAir I display. Be careful not to bend the pins.
4. Replace the cover to the electrical box.
5. Turn the breaker on to power the unit. Proceed with the programming.

Product Display/controller JP8 JP9 JP11 JP7

Self-contained o-Touch and o-LED display Jumper between No jumper Jumper between No jumper
and split units (the Micro Air OLED, what was 1 & 2 between 1 & 2 1&2 between 1 & 2
originally the MachAir II)
Factory setting 1 2 1 2 1 2 3 1 2

Self-contained MachAir I display Jumper between Jumper between Jumper between No jumper
and split units (the Micro Air FX-Maxx) 1&2 1&2 2&3 between 1 & 2

1 2 1 2 1 2 3 1 2

Figure 6. Control Board Jumper Settings

Marvair® Self-Contained and Split Systems Installation & Owner’s Manual 1/2011 Page 19 of 68
 Marvair® Reverse Cycle Air Conditioners

Pin Configuration for use with the o-Touch or o-LED display/controller

Pin Configuration for use with the MachAir I display/controller

Marvair® Self-Contained and Split Systems Installation & Owner’s Manual 1/2011 Page 20 of 68
 Marvair® Reverse Cycle Air Conditioners
Refrigerant Line Set and Charging (Split Systems only)
CAUTION
Keep refrigerant tubing clean prior to and during the installation.

Once the condensing section and the evaporator sections are located and secured, the two sections are
ready to be connected and charged with refrigerate, using the refrigerant tubing sizes shown in Table 9
“Refrigerant Line Sizes”.
Condensing unit Shutoff valve Shut off Valve
(BTUHs) Discharge Line Suction Line 0-24 ft.(0- 7.3m) 25-49 ft. (7.4-15m)
Liquid Suction Liquid Suction
7,000 ¼” flare 3/8” flare ¼” ½” ¼” ½”
10,000 ¼” flare 3/8” flare ¼” ½” 5/16” 5/8”
12,000 ¼” flare 3/8” flare ¼” ½” 5/16” 5/8”
16,000 & 18,000 ¼” flare ½” flare 5/16” 5/8” 3/8” 5/8”
24,000 3/8” flare 5/8” flare 5/16” 5/8” 3/8” ¾”
Table 9. Refrigerant Line Sizes

Insulate the vapor line with a minimum of ½” refrigerant pipe insulation to prevent condensation when
in the cooling mode and heat loss in the heating mode. The insulation should be installed on the tubing
prior to installation of the tubing and should run the entire length of the tube. The end of the tubing over
which the insulation is being slipped should be covered to prevent any insulation or foreign material from
entering the tube. When installing the tubing, be careful when bending the tubing to avoid any kinks.
Secure the tubing as required (minimum every 3 ft.).
Line set installation
1. Tubing must be cut square. Make certain that it is round and free of burrs. Clean the tubing to
prevent contaminants from entering the system.
2. Flare both ends of the tubing.
3. The evaporator section has a factory holding charge of nitrogen. Open the valves to release the
nitrogen before connecting the tubing.
4. Connect the suction and discharge lines to the shut off valves on the condenser and the
evaporator section.
5. Remove valve cap. Keep the cap in a clean place to ensure proper sealing and preventing
contaminants from entering the system.
6. Place refrigerant gauges on the shut off valve on the condenser section. Insert sufficient
refrigerant and check for leaks using soap suds or a liquid detergent. Bubbles indicate a leak. If a
leak is found, repair before proceeding.
7. After determining that the refrigerant is leak free, release the refrigerant.
8. Connect a vacuum pump to the refrigerant gages and pull a vacuum to 29.99 In. Hg.
9. Close gauges and turn pump off.
10. Remove the large hex head cap on the liquid line and using a # 10 Allen wretch, turn
Counterclockwise until it stops. Repeat on suction line.
11. Replace the hex head caps. The unit is ready to be charged.
12. Add refrigerant using standard charging procedures.
Marvair® Self-Contained and Split Systems Installation & Owner’s Manual 1/2011 Page 21 of 68
 Marvair® Reverse Cycle Air Conditioners
Chapter 5 - Thermostats and Controllers
Your Marvair® Marine unit is controlled by the o-Touch, o-LED or MachAir I thermostat controller. All
evaporator sections (models DEMH) for the split systems can be used with either the o-Touch, o-LED, or
the MachAir I thermostat/ controller. Please refer to the appropriate section of this manual for operating
your thermostat. Determine which unit you have installed and proceed with the appropriate instructions
for setting up the thermostat.

Self contained and split models have an air sensor factory
installed in front of the face of the evaporator coil. Make
sure the sensor is oriented so that air will be pulled across the
sensor. See photo at right.

The end of the sensor cable should be plugged into the Alt
Air port on the control board. See drawing on page 31.

Air Sensor
The solid state control board in the unit will operate all three displays. The board is factory configured to
operate the o-LED or the o-Touch displays. If you have the MachAir I display two pins must be moved
on the board. Refer to the set-up for the MachAir I controller, section 5.3, for instructions on moving the
pins. Before setting up either thermostat:

1. Turn the seacock valve to the open position

2. If the water pump has a dedicated breaker, turn it on. Verify that water is being discharged overboard.
3. Turn on the circuit breaker to the Marvair® unit.

Instructions for programming the o-Touch controller are in section 5.1, for the o-LED controller in 5.2
and for the MachAir I in section 5.3.

5.1 Instructions for the o-Touch Thermostat/Controller

General Description
The o-Touch is a digital display/controller that provides touch screen control of the temperature and
humidity, six fan speeds and shows fault conditions in a compact, easily readable display. The o-Touch
display/controller is designed to operate with Marvair self-contained and split system units.

A tap on the screen icons - set point temperature, fan speed and the operating mode- allows the user to
change the operation of the unit. Intuitive symbols enable the viewer to quickly see the operating status
of the unit and cabin temperature. If the display is not touched for 3 minutes, the display dims and
information scrolls across the screen. A light tap brings the display to bright.

In addition to controlling the environment, the o-Touch display controller also monitors the operation of
the Marvair unit and will display various fault conditions. If a problem is detected, a text message will
be displayed on the screen.

Marvair® Self-Contained and Split Systems Installation & Owner’s Manual 1/2011 Page 22 of 68
 Marvair® Reverse Cycle Air Conditioners
Alarm notifications include:
•• High or low refrigerant pressure.
•• Low AC voltage.
•• A failure or the internal sensor or a failure or improperly installed remote temperature sensor.
•• Water pump (requires optional sensor).
•• System over current.

The display connects to the board with a 15 ft. (457 cm) cable. Longer lengths of cable are available.

Features include:
•• High visibility Organic Light Emitting Diode display (OLED) offers superior visual characteristics
compared to LCD displays.
•• Variable brightness adjustment and automatic screen saver.
•• Four position menu navigation switch featuring a joystick style interface with push on / push off
control.
•• Built in room temperature sensor.
•• The display is compatible with Vimar and Gewiss frames.
•• Visual symbols enable the viewer to see the operating status at a glance.
•• Easily programmed for customized operation.
•• Both automatic and manual six level fan speed adjustment.
•• Built in options for fault protection for Voltage, Current and refrigerant pressure.
•• De-icing cycle to prevent evaporator icing.
•• Automatic moisture mode provides relative humidity control.
•• Universal 115/230 VAC 50/60 Hz power supply.

Optional features include:

•• Outside air temperature sensor.
•• Alternate air sensor.
•• Pump water sentry sensor.
•• DC fan control board featuring programmable speed control for up to four ultra-quiet
DC fans.
•• CAN computer area network capability.

When You Start:

1. Applying power: Turning the Thermostat/controller on
When power is first applied, the display will show the software revision, and then return to the last
state the unit was in when power was removed.
2. Touch screen operation:
To change a setting, gently tap on an icon. Excessive force will damage the display.
3. Operating states:
The display operates in two operational states. In the OFF state, the temperature is displayed, but
only fan operation is available. In the ON state, the display shows the temperature set point, room
temperature, fan, and operating mode. Switch between these states by tapping the On/Off (I/O) icon
in the lower left hand corner.

Marvair® Self-Contained and Split Systems Installation & Owner’s Manual 1/2011 Page 23 of 68
 Marvair® Reverse Cycle Air Conditioners
4.
Operating States

ON/OFF Icon Fan Speed

5. Screen Saver:
In screen saver, the display will appear dim and the information will scroll across the screen. Status
symbols appear as needed and operation continues in the mode selected. The brightness of the screen
in the screen saver mode can be changed in the program screen. See page 28, parameter no. 5. To
exit this mode, just tap the screen.

Operating Screens
Modes of Operation
The o-Touch has five modes of Operation – Cooling, Heating, Auto, Dehumidification and Fan Only.
Cooling, Heating, Auto and Dehumidification modes are selected by tapping the icon in the upper left
corner of the screen. In the Cooling, Heating and Auto Modes, the set point temperature is selected by
tapping the temperature (upper right hand corner). A screen appears with the temperature set point and
up and down arrows. Use the arrows to select the set point temperature. When the desired temperature
has been selected, tap the “X” to accept the set point.

Temperature Selection

UP Arrow Accept

DOWN Arrow

Fan Only Mode is selected by tapping the I/O icon to OFF. In the OFF position, only the fan will
operate.

Cooling Mode
To select cooling only, tap the mode select icon in the upper left hand corner of the display and scroll
through the symbols until the Cooling icon (a snowflake) appears. Set the desired room temperature
by tapping the temperature (upper right hand corner). A second screen appears with the temperature
set point and up and down arrows to adjust the temperature. When the desired temperature has been

Marvair® Self-Contained and Split Systems Installation & Owner’s Manual 1/2011 Page 24 of 68
 Marvair® Reverse Cycle Air Conditioners
selected, tap the “X” to accept the set point. The system will provide cooling as necessary.

Cooling Mode

Cooling Mode
Icon

Fan Speed
Indicator Room
Temperature

Heating Mode
To select heating only, tap the mode select icon in the upper left hand corner of the display and scroll
through the symbols until the Heating icon (a sun) appears. Set the desired room temperature by tapping
the up or down temperature (upper right hand corner). A second screen appears with the temperature
set point and up and down arrows to adjust the temperature. When the desired temperature has been
selected, tap the “X” to accept the set point. The system will provide heating as necessary.
Heating Mode

Heating Mode
Icon

Auto Mode
In the Auto mode, the unit will automatically heat or cool, depending upon the temperature set point.
To select the auto mode, tap the mode select icon in the upper left hand corner of the display and scroll
through the symbols until the Auto icon (one half snowflake/one half a sun) appears. Set the desired
room temperature by tapping the up or down temperature (upper right hand corner). A second screen
appears with the temperature set point and up and down arrows to adjust the temperature. When the
desired temperature has been selected, tap the “X” to accept the set point. The system will provide
cooling or heating as necessary.

Marvair® Self-Contained and Split Systems Installation & Owner’s Manual 1/2011 Page 25 of 68
 Marvair® Reverse Cycle Air Conditioners
Auto Mode

Auto
Changeover
Icon

Dehumidification Mode
Select this mode to help control humidity in the room while the room is unoccupied. To select moisture
mode, tap the mode select icon in the upper left corner to scroll through the symbols until the moisture
mode symbol (a water drop) appears. When the moisture mode is selected, the fan will run in low speed
for 30 minutes. After 30 minutes, the compressor will start and run in the cooling mode until the room
temperature drops 1ºF (2ºC), but no longer than one hour. This cycle will be repeated every 6 hours.
Note: the Dehumidification mode will not start if the room temperature is less than 70ºF (20ºC).
Dehumidification Mode

Dehumidification
Icon

Operating the Fan

Fan speed may be controlled automatically by room temperature or manually.

Options include:
•• Manual - the fan runs at a constant, user selected speed.
•• Auto - The Fan will automatically change speeds, depending on the difference between the set
point temperature and the temperature in the cabin. The fan will start on maximum speed. As
the temperature in the cabin approaches the set pint temperature, the fan will slow down to the
minimum speed.
•• Continuous – the fan runs continuously. The compressor cycles on & off to maintain the desired
temperature.

To set the desired fan operation and fan speed, tap the fan icon (lower right hand corner) to cycle
through fan speeds and automatic operation. Manually selected fan speed is indicated with an “M”

Marvair® Self-Contained and Split Systems Installation & Owner’s Manual 1/2011 Page 26 of 68
 Marvair® Reverse Cycle Air Conditioners
showing to the left of the speed indicator. When the fan is automatically controlled, the “M” is not
present. The fan may be controlled in the cool, heat, automatic modes as well as in the “Off” state to
circulate room air. In the “Off” state, the fan speed can be adjusted and turned off if desired.

Manual fan speed operation is not available when the compressor is not running if the cycle fan option
is set. In this case, turn the unit off and then manual fan operation may be used. Manual fan speed
operation is not available in moisture mode.

Manual Fan Speed Operation

Manual Fan
Speed Indicator

Outside Air Temperature

If the optional outside air temperature sensor is installed, the temperature set point in the
upper right of the display will alternate with OAT showing the outside air temperature.

Factory Defaults
To revert back to the factory default settings, enter the program mode and scroll thru to last parameter,
“Reset Parameters” appears. Select Reset Parameters.

Viewing System Status

In the ON state, press and hold the Mode select button for two seconds. The display will indicate
AC line voltage, System current, AC Line frequency, and High and Low pressure switch status and
condenser coil temperature if optional sensor is installed.

Fault Messages
The following fault messages will be shown on the display in the event of a failure. Repeated faults are
an indication of a problem and should be checked by a qualified service person. See the Troubleshooting
section of this manual for a more complete discussion for the causes of the fault messages and possible
remedies.

Marvair® Self-Contained and Split Systems Installation & Owner’s Manual 1/2011 Page 27 of 68
 Marvair® Reverse Cycle Air Conditioners
Fault Message Possible Cause
High Refrigerant Pressure Low or no water flow (cooling mode) or inadequate air flow (heating mode)
Low Refrigerant Pressure Low water flow (heating mode) or inadequate air flow (cooling mode)
Low AC Voltage Less than minimum voltage at unit.
System Overcurrent Higher than maximum voltage at unit.
Check Water Pump Indicated that the water pump has failed. Requires optional pump sentry sensor.
Air Sensor Trouble Failed Air Sensor
Lockout See the Fail safe level under the Parameter Description for your Display/Thermostat.
Table 10. Fault Messages

Program Parameters
There are fifteen programmable parameters with their factory defaults described in this section. The
table below defines the parameter descriptions along with the permitted values and default settings. To
enter the program mode, press and hold the I/O icon for 5 seconds. NOTE: the display must be in the
“OFF” mode to enter the program mode.

Use the right arrow to advance to the next parameter and the left arrow to go back to the previous
parameter. Use the up and down arrows to change the parameters value. Exit the program mode when
finished by pressing and releasing the “X” or wait 60 seconds for the display to automatically to exit.

Description Default Value

1 Cycled fan Continuous Cycled or Continuous
2 Reverse fan in heat Reverse Reverse or Normal
3 System units °F °F or °C
4 Display brightness 15 4=Minimum 15=Maximum
5 Screen saver brightness 4 - and 1-8
6 Temperature calibration 0 Ambient +/- 10°F
7 Staging delay 15 5-135 Seconds
8 Failsafe Level 3 Off 1, 2, 3
9 Low AC line detection Off Off
75 to 100 (115VAC units)
175 to 200 (220 VAC units)
10 De-Ice time Off Off, 30 to 90 seconds
11 Pump sentry Off Off, 100°F to 150°F (37.8ºC to 65.6ºC)
12 Cycle pump Cycle Cycle or Continuous
13 Electric Heat No Electric Heat Electric Heat or No Electric Heat
14 Fan speed 1 30 30-90
15 Fan speed 2 35 30-90
16 Fan speed 3 40 30-90
17 Fan speed 4 45 30-90
18 Fan speed 5 55 30-90
19 Fan speed 6 85 30-90
20 Unit ID 1 For use in a CAN bus network to identify the Marvair marine unit.
21 Group ID 1 For use in a CAN bus network to identify the Marvair marine unit
and to group several units together to function and allow control as
one unit.
22 Reset Parameters No No or Yes
Table 11. Program Parameters

Marvair® Self-Contained and Split Systems Installation & Owner’s Manual 1/2011 Page 28 of 68
 Marvair® Reverse Cycle Air Conditioners
Parameter Description:
1. Cycled fan: When set for cycled, the fan will operate on demand. When set for continuous, the fan
will always run unless you turn the system off.
2. Reverse fan in heat: Fan speed will increase as the room temperature rises if this parameter is set
for reverse. If set for normal, fan speed will decrease as room temperature rises. This parameter only
works in heat mode and the fan must be set for automatic operation.
3. System units: Degrees Fahrenheit (°F) or degrees Celsius (°C) can be selected
4. Display brightness: Display brightness can be set from 4 to 15 to suit room lighting. Brightness will
change as the number is changed.
5. Screen saver brightness: If set for (-) then a single bar (-) will blink sequentially in the four corners
of the display. Number values from 1 to 8 can be set to suit room brightness and the unit will operated
as described in the screen saver section.
6. Temperature calibration: This parameter allows the user to calibrate the room air temperature
sensor. The room temperature will be displayed and can be adjusted +/-10 °F or +/-5°C
7. Staging delay: The compressor staging delay is provided for multi system installations where more
than one system is operating from the same power source. Set the Staging delays at different intervals
so only one compressor starts at a time when power is applied.
8. Fail safe level: There are four fail safe levels the controller can be set to operate: OFF, 1, 2, and 3.
The default is 3.
Off Do not detect or display any faults except air sensor failure
1 The controller will detect a fault but will not display the fault
Operation will stop until the fault is cleared.
2 The controller will detect and display all faults.
Operation will stop until the fault is cleared.
The controller will detect and display all faults.
3 Operation will stop until the fault is cleared.
After 4 faults the controller will LOCKOUT and prevent
further operation
If LOCKOUT appears in the display, the unit must be turned off
then on again with the Off/On button.
Table 12. Fail Safe Levels

9. Low AC line detection: When set, if the AC line voltage remains below the set value, the system
will follow the action set by the failsafe level.
10. De-Ice time: When set, the system will perform the evaporator de-icing program.
11. Pump sentry: This system can be equipped with an optional sensor to monitor the condenser coil
temperature. If the temperature exceeds the set value, the failure will be handled according to the
failsafe level. This failure will prompt the user to CHECK WATER PUMP. Plug the sensor into the
Outside jack. Outside air temperature is not available when this option is used.
12. Cycle pump: When set for cycle, the pump will run on demand. When set for continuous, the pump
will run continuously when the system is on.
13. Electric heat/ No electric heat: Set this parameter only if the system is equipped with an electric
heater. If the heater current will exceed 10 Amps, a contactor must be connected to the valve output
to use this feature.
Marvair® Self-Contained and Split Systems Installation & Owner’s Manual 1/2011 Page 29 of 68
 Marvair® Reverse Cycle Air Conditioners
14-19. Fan speed 1-6: These parameters are used to optimize fan performance and should be changed
only by qualified service personnel.
20. Unit ID: For use in a CAN bus network to identify the Marvair marine unit.
21. Group ID: For use in a CAN bus network to identify the Marvair marine unit and to group several
units together to function and allow control as one unit.
22. Reset parameters: To reset all parameters to factory defaults, select YES and then exit the
program mode by pressing the joystick center button. The display will show EEPROM RESET
then show the room temperature in the off mode.

Specifications
Set point range 55°F to 85°F (12.7°C to 29.4°C)

Ambient temperature range displayed 5°F to 150°F (-15ºC to 65.5ºC)

Sensor accuracy 2°F at 77°F (1.2ºC at 35ºC)

Low voltage limit 115 VAC units 75VAC

Low voltage limit 230 VAC units 175VAC

Line voltage limit 250VAC

Frequency 50 or 60 Hz

Fan output MAX 6 Amps

Valve output MAX 10 Amps

Pump output MAX ¼ HP at 115 VAC

½ HP at 230 VAC

Compressor output 1HP at 115 VAC

2HP at 230 VAC

Minimum operating temperature 0°F (-17.8ºC)

Maximum operating temperature 180°F (82ºC)

Maximum RH conditions 99% Non-condensing

Maximum length of the display cable 75 Feet (22.86 m)

Maximum length of the Outside air sensor cable 50 Feet (15.24 m)

Marvair® Self-Contained and Split Systems Installation & Owner’s Manual 1/2011 Page 30 of 68
 Marvair® Reverse Cycle Air Conditioners

Figure 7. o-Touch Electrical Schematic

Marvair® Self-Contained and Split Systems Installation & Owner’s Manual 1/2011 Page 31 of 68
 Marvair® Reverse Cycle Air Conditioners
5.2 Instructions for the o-LED Thermostat/Controller
General Description
The Marvair® digital controller operates onboard air conditioning equipment to provide room temperature
control and humidity reduction. It allows for easy adjustment of fan speed, operating mode and temperature
in a wide variety of applications. The Marvair® digital controller is designed to operate with self contained
and central type marine air-conditioning systems.
Features include:
•• High visibility Organic Light Emitting Diode display (OLED) offers superior visual characteristics
compared to LCD displays.
•• Variable brightness adjustment and automatic screen saver.
•• Four position menu navigation switch featuring a joystick style interface with push on / push off
control.
•• Built in room temperature sensor.
•• The display is compatible with Vimar and Gewiss frames.
•• Visual symbols enable the viewer to see the operating status at a glance.
•• Easily programmed for customized operation.
•• Both automatic and manual six level fan speed adjustment.
•• Built in options for fault protection for Voltage, Current and refrigerant pressure.
•• De-icing cycle to prevent evaporator icing.
•• Automatic moisture mode provides relative humidity control.
•• Universal 115/230 VAC 50/60 Hz power supply.
Optional features include:
•• Outside air temperature sensor.
•• Alternate air sensor.
•• Pump sentry water sensor.

When You Start:

1. Applying power: Turning the Thermostat/controller on
When power is first applied, the display will show the software revision, and then return to the last
state the unit was in when power was removed.

On/Off Button Up Button

Mode Select Fan Operation

Button Button

Down Button

Joystick operation:
The four position joystick may be tapped up, down, right, left or in the center to make changes to
the operation of the control. Gently tap this switch to operate it. Excessive force will damage the
switch.

Marvair® Self-Contained and Split Systems Installation & Owner’s Manual 1/2011 Page 32 of 68
 Marvair® Reverse Cycle Air Conditioners
2. Operating states:
The display operates in two operational states. In the OFF state, the temperature is displayed and
only fan operation is available. In the ON state, the display shows the temperature set point, room
temperature, fan, and compressor status. Switch between these states by pressing and releasing the On/
Off button.
4. Symbol animation:
Some symbols on the display use animation to indicate operation of part of the system.

Operating Screens
Screen Saver
In screen saver, the display will appear dim and the information will scroll across the screen. Status
symbols appear as needed and operation continues in the mode selected. The brightness of the screen in
the screen saver mode can be changed in the program screen. See page 13, parameter no. 4. To exit this
mode, just tap any button.

Screen Saver

Room
Temperature

Cool Mode
Symbol Fan Operating

Compressor Status

Cool Mode
To select cooling only, tap the mode select button to scroll through the symbols in the top left of the display
until the cool symbol appears. Set the desired room temperature by tapping the up or down button. The
system will provide cooling as necessary. The compressor symbol will appear when system is cooling.

Room Air
Cool Mode Temperature

Cool Mode Temperature

Symbol Set Point

Compressor
Status

Fan Speed Fan Operating

Indicator

Heat Mode
To select heating only, tap the mode select button to scroll through the symbols in the top left of the
Marvair® Self-Contained and Split Systems Installation & Owner’s Manual 1/2011 Page 33 of 68
 Marvair® Reverse Cycle Air Conditioners
display until the heat symbol appears. Set the desired room temperature by tapping the up or down button.
The system will provide heating as necessary. The compressor symbol will appear when the system is
heating.
Heat Mode Room Air
Temperature
Heat Mode Temperature
Symbol Set Point

Compressor
Status

Fan Speed Fan Operating

Indicator

Automatic Mode
To select automatic mode, tap the mode select button to scroll through the symbols in the top left of the
display until the automatic mode symbol appears. In this mode, the system will automatically maintain
room temperature. Set the desired room temperature by tapping the up or down joystick button. When the
system is operating, the appropriate symbol will appear in the lower left corner.
Room Air
Automatic Mode Temperature

Automatic Mode Temperature

Symbol Set Point

Compressor
Status

Fan Speed Fan Operating

Indicator

Moisture Mode
Select this mode to help control humidity in the room while the room is unoccupied. To select moisture
mode, tap the mode select button to scroll through the symbols in the top left of the display until the moisture
mode symbol appears. When the moisture mode is selected, the fan will run in low speed for 30 minutes.
After 30 minutes, the compressor will start and run in the cooling mode until the room temperature drops
(2ºC), but no longer than one hour. This cycle will be repeated every 6 hours. Note: the Dehumidification
mode will not start if the room temperature is less than 70ºF (20ºC).
Moisture Mode

Moisture
Mode
Symbol

Room Air
Temperature
Marvair® Self-Contained and Split Systems Installation & Owner’s Manual 1/2011 Page 34 of 68
 Marvair® Reverse Cycle Air Conditioners
Operating the Fan
Fan speed may be controlled automatically by room temperature or manually. Tap the joystick fan button
to cycle through fan speeds and automatic operation. Manually selected fan speed is indicated with the M
showing before the speed indicator. When the fan is automatically controlled, the M is not present. The fan
may be controlled in the cool, heat, automatic modes as well as in the “Off” state to circulate room air. In
the “Off” state, the fan speed can be adjusted and turned off if desired.
Manual fan speed operation is not available when the compressor is not running if the cycle fan option is
set. Turn the unit off in this case and then manual fan operation may be used. Manual fan speed operation
is also not available in moisture mode.
Manual Fan Low Manual Fan High
Animated
Symbol

Fan Speed
Indicator
“M” = Manual Fan Fan Operation Button

Outside Air Temperature

If the optional outside air temperature sensor is installed, the temperature set point
in the upper right of the display will alternate with OAT showing outside air temperature.

Factory Defaults
To revert back to the factory default settings:
With the Thermostat in the OFF setting,

1. Use the joy stick, press in the following sequence: Mode, Up, Down and Mode again.
2. Use the fan button to advance to the Reset Parameters screen. This is the last screen.
3. Use the Up/Down button and select “YES”.

Viewing System Status

In the ON state, press and hold the Mode select button for two seconds. The display will indicate AC line
voltage, System current, AC Line frequency, and High and Low pressure switch status and condenser coil
temperature if optional sensor is installed.

Fault Messages
The following fault messages will be shown on the display in the event of a failure. Repeated faults are
an indication of a problem and should be checked by a qualified service person. See the Troubleshooting
section of this manual for a more complete discussion for the causes of the fault messages and possible
remedies.

Marvair® Self-Contained and Split Systems Installation & Owner’s Manual 1/2011 Page 35 of 68
 Marvair® Reverse Cycle Air Conditioners
Fault Message Possible Cause
High Refrigerant Pressure Low or no water flow (cooling mode) or inadequate air flow (heating mode)
Low Refrigerant Pressure Low water flow (heating mode) or inadequate air flow (cooling mode)
Low AC Voltage Less than minimum voltage at unit.
System Overcurrent Higher than maximum voltage at unit.
Check Water Pump Indicated that the water pump has failed. Requires optional pump sentry sensor.
Air Sensor Trouble Failed Air Sensor
Lockout See the Fail safe level under the Parameter Description for your Display/Thermostat.
Table 13. Fault Messages

Program Parameters
There are fifteen programmable parameters with their factory defaults described in this section. The table
below defines the parameter descriptions along with the permitted values and default settings.
To enter the program mode first put the unit in the off state. Next press the following sequence of buttons:
Mode, Up, Down, Mode. Use the fan button to advance to the next parameter and the mode button to go back
to the last parameter. Use the up and down buttons to change the parameters value. Exit the program mode
when finished by pressing and releasing the On/Off button or wait 60 seconds for the display to exit.
Description Default Value
1 Cycled fan Continuous Cycled or Continuous
2 Reverse fan in heat Reverse Reverse or Normal
3 System units °F °F or °C
4 Display brightness 15 4=Minimum 15=Maximum
5 Screen saver brightness 4 - and 1-8
6 Temperature calibration 0 Ambient +/- 10°F
7 Staging delay 15 5-135 Seconds
8 Failsafe Level 3 Off 1, 2, 3
Low AC line detection Off Off
9 75 to 100 (115VAC units)
175 to 200 (220 VAC units)
10 De-Ice time Off Off, 30 to 90 seconds
11 Pump sentry Off Off, 100°F to 150°F (37.8ºC to 65.6ºC)
12 Cycle pump Cycle Cycle or Continuous
13 Electric Heat No Electric Heat Electric Heat or No Electric Heat
14 Fan speed 1 30 30-90
15 Fan speed 2 35 30-90
16 Fan speed 3 40 30-90
17 Fan speed 4 45 30-90
18 Fan speed 5 55 30-90
19 Fan speed 6 85 30-90
20 Reset Parameters No No or Yes
Table 14. Program Parameters
Parameter Description:
14. Cycled fan: When set for cycled, the fan will operate on demand. When set for continuous, the fan
will always run unless you turn the system off.
15. Reverse fan in heat: Fan speed will increase as the room temperature rises if this parameter is set
for reverse. If set for normal, fan speed will decrease as room temperature rises. This parameter only
works in heat mode and the fan must be set for automatic operation.
Marvair® Self-Contained and Split Systems Installation & Owner’s Manual 1/2011 Page 36 of 68
 Marvair® Reverse Cycle Air Conditioners
16. System units: Degrees Fahrenheit (°F) or degrees Celsius (°C) can be selected
17. Display brightness: Display brightness can be set from 4 to 15 to suit room lighting. Brightness will
change as the number is changed.
18. Screen saver brightness: If set for (-) then a single bar (-) will blink sequentially in the four corners
of the display. Number values from 1 to 8 can be set to suit room brightness and the unit will operated
as described in the screen saver section.
19. Temperature calibration: This parameter allows the user to calibrate the room air temperature
sensor. The room temperature will be displayed and can be adjusted +/-10 °F or +/-5°C
20. Staging delay: The compressor staging delay is provided for multi system installations where more
than one system is operating from the same power source. Set the Staging delays at different intervals
so only one compressor starts at a time when power is applied.
21. Fail safe level: There are four fail safe levels the controller can be set to operate: OFF, 1, 2, and 3.
The default is 3.
Off Do not detect or display any faults except air sensor failure
1 The controller will detect a fault but will not display the fault
Operation will stop until the fault is cleared.
2 The controller will detect and display all faults.
Operation will stop until the fault is cleared.
The controller will detect and display all faults.
3 Operation will stop until the fault is cleared.
After 4 faults the controller will LOCKOUT and prevent
further operation
If LOCKOUT appears in the display, the unit must be turned off
then on again with the Off/On button.
Table 15. Fail Safe Level

22. Low AC line detection: When set, if the AC line voltage remains below the set value, the system
will follow the action set by the failsafe level.
23. De-Ice time: When set, the system will perform the evaporator de-icing program.
24. Pump sentry: This system can be equipped with an optional sensor to monitor the condenser coil
temperature. If the temperature exceeds the set value, the failure will be handled according to the
failsafe level. This failure will prompt the user to CHECK WATER PUMP. Plug the sensor into the
Outside jack. Outside air temperature is not available when this option is used.
25. Cycle pump: When set for cycle, the pump will run on demand. When set for continuous, the pump
will run continuously when the system is on.
26. Electric heat/ No electric heat: Set this parameter only if the system is equipped with an electric
heater. If the heater current will exceed 10 Amps, a contactor must be connected to the valve output
to use this feature.
14-19. Fan speed 1-6: These parameters are used to optimize fan performance and should be changed
only by qualified service personnel.
20. Reset parameters: To reset all parameters to factory defaults, select YES and then exit the program
mode by pressing the joystick center button. The display will show EEPROM RESET then show the
room temperature in the off mode.
Marvair® Self-Contained and Split Systems Installation & Owner’s Manual 1/2011 Page 37 of 68
 Marvair® Reverse Cycle Air Conditioners
Specifications
Set point range 55°F to 85°F (12.7°C to 29.4°C)

Ambient temperature range displayed 5°F to 150°F (-15ºC to 65.5ºC)

Sensor accuracy 2°F at 77°F (1.2ºC at 35ºC)

Low voltage limit 115 VAC units 75VAC

Low voltage limit 230 VAC units 175VAC

Line voltage limit 250VAC

Frequency 50 or 60 Hz

Fan output MAX 6 Amps

Valve output MAX 10 Amps

Pump output MAX ¼ HP at 115 VAC

½ HP at 230 VAC

Compressor output 1HP at 115 VAC

2HP at 230 VAC

Minimum operating temperature 0°F (-17.8ºC)

Maximum operating temperature 180°F (82ºC)

Maximum RH conditions 99% Non-condensing

Maximum length of the display cable 75 Feet (22.86 m)

Maximum length of the Outside air sensor cable 50 Feet (15.24 m)

Marvair® Self-Contained and Split Systems Installation & Owner’s Manual 1/2011 Page 38 of 68
 Marvair® Reverse Cycle Air Conditioners

Figure 8. o-LED Electrical Schematic

Marvair® Self-Contained and Split Systems Installation & Owner’s Manual 1/2011 Page 39 of 68
 Marvair® Reverse Cycle Air Conditioners
5.3 Instructions for the MachAir I Controller
The Marvair® reverse cycle air conditioner utilizes the MachAirTM 1
Controller and Display which has a universal power supply that
operates on 115V or 240V and 50 or 60 Hz AC power.

Standard Features

• User friendly 6 button display panel requires no manual for

basic operation
• Five-volt logic and micro controller located on the display
• 3-digit, 7-segment display panel indicates degrees Fahrenheit or Centigrade
• Paintable Face Plate Cover with recess for matching wall covering insert
• Automatic fan speed reduction as set point is approached
• Six (6) programmable manual fan speeds
• AC voltmeter to protect valuable electrical components
• 16 programmable parameters for custom installations
• High and low refrigerant pressure switch inputs
• Moisture Mode for controlling relative humidity
• De-Icing cycle to prevent evaporator coil icing
• Universal AC Power Supply
• Non-volatile memory retains settings without batteries
• Programmable display brightness control for night use

Optional Features
The following optional items can be added by plugging the device into the appropriate jack and making
the necessary programming changes.

• Outside Air Temperature Sensor - No Programming Necessary

• Alternate Air Temperature Sensor - No Programming Necessary
• Custom Paintable Display Panels
• Pump Guard Water Sensor - Program Setting of P-8 is Required

This manual is intended to provide the information necessary to ensure proper installation and operation
of MachAir Controller. Improper installation and/or misunderstood operating parameters will result in
unsatisfactory performance and premature failure of the MachAir Controller.

Your Marvair® reverse cycle air conditioner has a solid state control board located in the electrical box on
the unit. This control board is compatible for use with either the o-Touch or o-LED display or the MachAir
I display. The board is configured at the factory for the o-Touch or o-LED display. To use the board with
the MachAir I display, two pins must be moved on the control board. The pins should be removed by hand;
do not use pliers or a screw driver to remove the pins.

Marvair® Self-Contained and Split Systems Installation & Owner’s Manual 1/2011 Page 40 of 68
 Marvair® Reverse Cycle Air Conditioners
1. Turn off the power to the Marvair® unit at the breaker.
2. Remove the cover to the electrical box.
3. Carefully pull the two clips on JP11 & JP9 and move them to the position for use with the MachAir
I display. Be careful not to bend the pins.
4. Replace the cover to the electrical box.
5. Turn the breaker on to power the unit. Proceed with the programming.

Pin Configuration for use with the MachAir I display/controller

Product Display/controller JP8 JP9 JP11 JP7

Self-contained o-Touch and o-LED display Jumper between No jumper Jumper between No jumper
and split units (the Micro Air OLED, what was 1 & 2 between 1 & 2 1&2 between 1 & 2
originally the MachAir II)
Factory setting 1 2 1 2 1 2 3 1 2

Self-contained MachAir I display Jumper between Jumper between Jumper between No jumper
and split units (the Micro Air FX-Maxx) 1&2 1&2 2&3 between 1 & 2

1 2 1 2 1 2 3 1 2

Figure 9. Control Board Jumper Settings

Marvair® Self-Contained and Split Systems Installation & Owner’s Manual 1/2011 Page 41 of 68
 Marvair® Reverse Cycle Air Conditioners
Basic Operation
POWER BUTTON Press the POWER button once to toggle the unit to the “ON” mode. Press the
POWER button again to toggle the unit to the “OFF” mode.

FAN SPEED BUTTON Press and release the FAN SPEED button to advance from “AUTO” to
“MANUAL” fan operation. Press and release to increase the manual fan speeds, to settings “1 through
6”. Press and release again, returns it to the “AUTO” fan mode. The selected fan mode is identified by the
LED’s for “AUTO” and “MANUAL”.

UP BUTTON Momentarily press and the set point will appear in the temperature display. The set point
increases one degree each time the UP arrow button is pressed and released.

DOWN BUTTON Momentarily press and release to display the set point. The set point is decreased one
degree each time the DOWN arrow button is pressed and released.

MODE BUTTON The MODE button is used to select one of 4 Operating Modes. Press and release to
advance to the next mode. Continue to press and release until the desired Operating Mode is reached. The
mode selected is indicated by the Mode LED.

TEMP SELECT BUTTON Press and release to view the inside (supply) air temperature, outside
(return) air temperature or set point. The appropriate LED will be lit indicating that temperature is being
displayed.

THREE DIGIT DISPLAY The inside (supply) temperature is displayed whenever the control is turned
on. The display provides a readout of the inside air temperature which is located in the supply duct.

HEAT MODE LED The “HEAT” mode LED is lit when Heating is selected.

COOL MODE LED The “COOL” mode LED is lit when Cooling is selected.

AUTO LED The “AUTO” mode LED is lit when the Automatic Heating or Cooling mode is selected.
The control will automatically switch to heating or cooling when this mode is selected.

MOISTURE CONTROL LED The “MOISTURE CONTROL” LED is lit when Moisture Control is
selected.

MANUAL FAN LED The “MANUAL” Fan Speed LED is lit when the fan speed has been manually
selected.

AUTO FAN LED The “AUTO” Fan Speed LED is lit when the fan speed has been automatically
selected.

FAN SPEED BAR GRAPH There are six (6) individual fan speed LED’s. Each LED represents one (1)
fan speed. The lowest fan speed setting is indicated by illuminating the first LED. The highest fan speed
setting is indicated by illuminating all six LED’s.

LED The system operating status (Compressor On or Off) is indicated by turning on the right most
decimal point in the 3 Digit Display.

Marvair® Self-Contained and Split Systems Installation & Owner’s Manual 1/2011 Page 42 of 68
 Marvair® Reverse Cycle Air Conditioners
System Overview
Press the POWER button once to engage the system. The Display indicates room temperature when the
system is on and the display is blank when the system is off.

Press and release the MODE Button until the desired Mode LED is illuminated.

Set the desired room temperature by pressing the Up or Down arrow buttons. The set point can viewed by
momentarily pressing and releasing the Up or Down arrow buttons.

Fan speed operation is automatic allowing fan speed to decrease as room temperature is approached. The
fan speed decreases as the set point is approached. The fan will operate at low speed when the set point is
satisfied. Manual fan speeds can be selected by pressing and releasing the FAN SPEED button to select
the desired manual fan speed. The fan will operate at the speed selected and will not change speeds with
room temperature.

The fan can be programmed to cycle on and off with demand, allowing the fan to run only when cooling or
heating is required. Normally the automatic fan speed operation is reversed in the heating mode, however,
the fan can be programmed to operate the same as in the cooling mode.

Normal Heating or Cooling Cycle

Select COOL mode and cooling only will be provided. The cabin temperature will be maintained within
2°F of the set point. Select HEAT mode and heating only will be supplied. The cabin temperature will be
maintained within 2°F of the set point.

Select AUTO and either heating or cooling will be supplied when it is required. While in the automatic
mode the controller will maintain the set point within a 2°F temperature variation. A four degree swing
is required to cause the unit to shift to the opposite mode. Once in a given mode, heating or cooling, the
controller will maintain a 2 degree differential.

When the heating or cooling demand is satisfied, the compressor cycles off and the automatic fan returns
to low speed. The fan speed will remain constant if MANUAL Fan Speed had been selected.

Reversing Valve Operation

The reversing valve is toggled to the opposite mode (for pressure equalization) when heating or cooling
is required to reduce the compressor’s starting requirements and the electrical power surge. The valve
will only toggle to the opposite mode when a cooling or heating cycle is called for and if the system has
been off for less than seventy-five (75) seconds. The valve will also toggle if a cycle is interrupted from
the display panel by pressing the POWER button On/Off, or by changing the set point. Unnecessary
valve toggling has been limited to reduce reversing valve noise. Valve toggling can be totally eliminated
by programming the minimum compressor staging delay at seventy-five (75) seconds or greater.

Power on reset, which occurs when the system is powered up, will always initiate a valve toggle.

Controller Memory
The MachAir Controller has non-volatile memory which requires no batteries or any form of backup
power. When power is lost, the operating parameters are retained indefinitely. When power is restored,
the controller resumes operation as last programmed. All operating and programming parameters are
entered into non-volatile memory instantly and are retained indefinitely.

Marvair® Self-Contained and Split Systems Installation & Owner’s Manual 1/2011 Page 43 of 68
 Marvair® Reverse Cycle Air Conditioners
Operator Controls and Display Panel
1. POWER BUTTON The POWER button is used to toggle between the On and Off modes. Press
the POWER button once to toggle the unit to the On mode. Press the POWER button again to
toggle the unit to the Off mode.
2. FAN SPEED BUTTON Press and release the FAN SPEED button to advance from AUTO to
MANUAL fan. Press and release the FAN SPEED button to advance the manual fan speeds, from
1 through 6. Press and release again to return to the AUTO fan mode. The selected fan mode is
indicated by the AUTO and MANUAL fan LED’s.
3. UP ARROW BUTTON Momentarily press the UP arrow button and the set point will appear in
the temperature display. Press and release the UP arrow button to increase the set point one degree.
The set point is increased by one degree each time the UP arrow button is pressed and released.
The highest set point allowed is 85ºF (39.4ºC). The UP arrow button is used in conjunction with the
DOWN arrow button to display the outside air temperature when the control is on. The UP arrow
button is also used to increase program values in the program mode.
4. DOWN ARROW BUTTON Momentarily press and release the DOWN arrow button to display
the set point. Press and release the DOWN arrow button to decrease the set point. The set point is
decreased one degree each time the DOWN arrow button is pressed and released. The lowest set
point allowed is 55ºF (12.8ºC). The DOWN arrow button is used in conjunction with the UP arrow
button to display the outside temperature when the control is on. The DOWN arrow button is also
used to reduce program values in the program mode.
5. MODE BUTTON The MODE button is used to select one of the four operating modes. Press
and release the MODE button and the controller will advance to the next mode. Continue to press
and release the MODE button until the desired operating mode is reached. The mode selected is
indicated by the MODE LED, i.e., COOL, HEAT, AUTO or MOISTURE CONTROL.
6. TEMP SELECT BUTTON Press and release the TEMP SELECT button to view inside air
temperature, outside air temperature or the set point. The appropriate LED, INSIDE, OUTSIDE or
SET POINT will be illuminated indicating which temperature is being displayed. If no outside air
sensor is installed three (3) dashes will appear in the Three Digit Display.
7. THREE DIGIT SEVEN SEGMENT DISPLAY The inside air temperature is displayed in the
window whenever the control is turned on. The three digit 7 segment display provides a readout
of the inside air temperature which is located in the face plate. An optional alternate air sensor is
available for installations that can not use the face plate sensor.

The display also indicates program information, fault codes and outside air temperature when the
optional alternate air sensor is installed.

The display momentarily indicates the SET POINT when the UP or DOWN arrow button is
pressed.

When the control resumes operation after a power interruption all the display LED’s will turn on for
one second. This is a normal operating condition and is referred to as “Power On Reset”.
8. HEAT MODE LED The HEAT mode LED will be illuminated when the Heating Mode has been
selected. The HEAT mode LED is also illuminated when optional electric heat is installed and the
Marvair® Self-Contained and Split Systems Installation & Owner’s Manual 1/2011 Page 44 of 68
 Marvair® Reverse Cycle Air Conditioners
Heating Mode has been selected. Electric heater status, On or Off, is indicated by the right most
decimal point (see Item 18).
9. COOL MODE LED The COOL mode LED will be illuminated when the Cooling Mode has been
selected.
10. AUTO LED The AUTO LED is illuminated when the Automatic Heating or Cooling Mode has
been selected. The controller will automatically switch to Heating or Cooling when this mode is
selected.
11. MOISTURE CONTROL LED The MOISTURE CONTROL mode LED is illuminated when
Moisture Control has been selected. This mode is used to control humidity during periods when the
vessel is unoccupied.
12. MANUAL FAN SPEED LED The MANUAL Fan Speed LED will be illuminated when one of the
six (6) Manual Fan Speeds has been selected.
13. AUTO FAN SPEED LED The AUTO Fan Speed LED is illuminated when Automatic Fan Speed
is functioning.
14. FAN SPEED BAR GRAPH There are six (6) individual Fan Speed LED’s in the Fan Speed Bar
Graph. Each LED represents one (1) Fan Speed. Low Fan Speed 1 is indicated by illuminating the
first LED. High Fan Speed 6 is indicated by illuminating all six (6) LED’s. Any of the six (6) Fan
Speeds available are displayed by the illuminated corresponding number of LED’s.
15. INSIDE LED The INSIDE LED is illuminated when the Inside Air Temperature is being
displayed.
16. OUTSIDE LED The OUTSIDE LED is illuminated when the outside air temperature is
displayed.
17. SET POINT LED The SET POINT LED is illuminated when the Set Point is displayed.
18. COMPRESSOR LED The system operating status (Compressor On or Off) is indicated by turning
on the right most decimal point in the 3 Digit Display.

Dual Button Functions

UP & DOWN ARROW BUTTONS Press the UP and DOWN arrow buttons together and the outside air
temperature will be displayed, providing the Optional Outside Air Temperature Sensor has been installed.
No programming is required. Press the UP and DOWN arrow buttons simultaneously, while in the
program mode, to set new custom programming defaults.

POWER BUTTON & DOWN ARROW BUTTON Simultaneously pressing the POWER button and
the DOWN arrow button while viewing the Service Fault History Log clears the fault History Log.

Special Button Functions

Special button functions are implemented by pressing and holding a particular button while the control’s
AC power is turned on.

1. Service History Log View the service history log by pressing and holding the MODE button while
turning on the AC power. Exit the service history log by pressing the POWER button once. Clear the

Marvair® Self-Contained and Split Systems Installation & Owner’s Manual 1/2011 Page 45 of 68
 Marvair® Reverse Cycle Air Conditioners
service history log by simultaneously pressing the POWER button and the DOWN arrow button.

2. Self Test Mode Press and hold the POWER button while AC power is applied to enter the self test
mode. The self test mode is used to diagnose problems and to test the air conditioning system.

3. View Hour Meter To view the compressor hour meter, press and hold the DOWN arrow button while
applying AC power. Maximum recorded time is 10,000 hours. The hour meter stops at maximum
(10,000 hrs) and can only be reset by the Manufacturer.

Modes of Operation
Off Mode
When the controller is in the Off Mode, all control outputs are turned off. Program parameters and
user settings are saved in a non-volatile memory. The program mode can only be accessed from the Off
Mode.

On Mode
When the controller is in the On Mode, power will be supplied to the appropriate control outputs and the
display will indicate the current state of operation. The operating and program parameters resume based
on those stored the last time the unit was operating.

Cool Only Mode

When the COOL LED is on, only the Cooling systems are selected and operated as required. When the
temperature drops below the set point, the system will not automatically switch to the Heating Mode.
Cooling only is available for customers that do not want automatic Cooling and Heating operation.
Systems without reverse cycle heating can have an optional electric heater installed should heating be
required.

Heat Only Mode

When the HEAT LED is on, only the Heating systems are selected and operated as required. Should
the temperature rise above the set point, the system will not automatically switch to the Cooling mode.
Heating only is supplied for customers that require the system to not automatically switch from the
Heating to the Cooling mode.

Automatic Mode
When the AUTO LED is on, either Heating or Cooling are supplied as required. The HEAT and COOL
LED’s will be illuminated according to the mode required. When the system requires compressor operation
for Heating or Cooling the right most decimal point will turn on when the compressor is on.

Temperature in a given mode will be maintained at two degrees Fahrenheit (2°F), however, a four degree
difference is required to allow the controller to change modes. Once in a new mode, the temperature will
remain within two degrees Fahrenheit (2ºF) of the set point.

Moisture Control Mode

While in the on mode, press the MODE button until the MOISTURE CONTROL mode LED is
illuminated. Every four (4) hours, the fan is started and air is circulated for thirty (30) minutes. During this
time the air temperature is sampled and entered into memory. The cooling cycle is started and continues
until the temperature is lowered 2°F. The compressor is allowed a maximum of one hour running time to
Marvair® Self-Contained and Split Systems Installation & Owner’s Manual 1/2011 Page 46 of 68
 Marvair® Reverse Cycle Air Conditioners
reach the desired temperature. Four (4) hours after the temperature is satisfied on the compressor the cycle
will be repeated. The right most decimal point is illuminated while the compressor is running.

Fan Speed Modes

Auto Fan Speed Mode
The controller has six automatic fan speeds available. Speed 6 is high, 3 is medium and 1 is low or
the slowest speed. AUTO Fan Speed mode allows the controller to determine the required fan speed
based on room temperature. The closer the room temperature is to the set point, the slower the fan will
run. This permits a balance between the most efficient temperature control and the slower/quieter fan
speeds. Automatic Fan Speed operation is the factory default, however, MANUAL Fan Speed mode is
available.

Manual Fan Speed Mode

The controller has six automatic fan speeds available. Speed 6 is high, 3 is medium and 1 is low or the
slowest speed. MANUAL Fan Speed mode allows the user to select and maintain the desired fan speed
manually. When a MANUAL Fan Speed has been selected, the Fan Speed Bar Graph will indicate the
speed selected by the number of LED’s illuminated. Select Fan Speed 3, for example, and the first three
LED’s in the Fan Speed Bar Graph will turn on. MANUAL Fan Speed mode is sometimes preferred when
room temperature is constantly changing due to varying heat loads.

Program Mode
Program Mode Overview
The program mode is used to adjust the systems operating parameters to suit the particular needs of
individual users. The program mode is also used to tailor the air conditioning system for the most efficient
operation within an installation. Installation variables such as ducting, sensor location and system layout
effect the perceived operation of the overall system. The program mode allows the system to operate as
efficiently as possible under all conditions. The controller is shipped with factory programmable default
settings which are stored in permanent memory and can be recalled at any time.

Warning
Severe electrical disturbances can sometimes upset the controller operating sequences. Operator confusion
related to program parameters can also cause, what seem to be, operational problems. Whenever there is any
doubt as to the proper operation of the controller, Factory Default Parameters, should be re-initialized.

Entering Program Mode

The program mode can only be entered from the Off Mode. From the Off Mode and in the following order,
press the TEMP SELECT, UP arrow, DOWN arrow and TEMP SELECT buttons. These buttons have
to be pressed and released in the order given. The numerals “85” which represent the high Fan Speed limit,
appear in the display. The “85” is followed by the characters “P1” followed again by the parameter setting
(“85”). P1 represents the first programmable parameter. The controller is now in the program mode. Exit
the program mode, to the Off Mode, by pressing and releasing the POWER button.

NOTE: The controller will exit the program mode and return to the Off Mode if no programming is
attempted for one (1) minute.

Marvair® Self-Contained and Split Systems Installation & Owner’s Manual 1/2011 Page 47 of 68
 Marvair® Reverse Cycle Air Conditioners
Restore Memorized Default Settings
The memorized default settings can be restored by entering the program mode and setting P-16 to rSt. Exit
the program mode and the software version number appears in the display. The memorized default settings
are restored and the controller returns to the Off Mode. The software version number is always displayed
when you exit the program mode.

Increment from one parameter to the next by pressing and releasing the MODE button while in the
program mode. Use the UP arrow and DOWN arrow buttons to change the program parameter values. The
programmable parameters range from P-1 through P-16.

Up and Down Buttons

The UP arrow and DOWN arrow buttons are used to select the data or set the desired limits for the
parameters being programmed. This method is followed throughout the program mode, however, special
instructions are included for individual functions that require them.

Exiting the Program Mode

There are two methods to exit the program mode. Press the POWER button and the controller will return
to the Off Mode. Not pressing any buttons or attempting any program changes for sixty (60) seconds will
allow the controller to exit the Program Mode to the Off Mode. Any programming changes that were made
while in the program mode will be memorized and put into operation when the program mode is exited
and the controller is returned to the On Mode.

Marvair® Self-Contained and Split Systems Installation & Owner’s Manual 1/2011 Page 48 of 68
 Marvair® Reverse Cycle Air Conditioners
Programming
Programmable Parameters
There are sixteen (16) programmable parameters with their Factory Default Settings listed in this section.
The table below indicates what these parameters are, along with the permitted values and the original
Factory Default Settings.
Program
Description Default Range
Number
P-1 High Fan Speed Limit (arbitrary units) 85 56 to 85
P-2 Low Fan Speed Limit (arbitrary units) 50 30 to 55
P-3 Compressor Staging Time Delay 15 5 to 135 seconds
P-4 Temperature Sensor Calibration 0 Ambient + 10oF
Failsafe Modes and Mnemonic 3 = 4 Failures With Off
High refrigerate Pressure (HPF) 90 Second Restart 1 = Continuous No Display
P-5
Low refrigerate Pressure (LPF) Delay. Manual Reset 2 = Continuous With Display
Low AC Line Voltage (LAC) is Required 3 = 4 Failures Reset Required
85 VAC (115 vac) Off - 75 to 100 (115 vac Units)
P-6 Low AC Voltage Cut-Off
185 VAC (230 vac) Off - 175 to 200 (220 vac Units)
O = Off
P-7 De-Icing Cycle O
1 to 3 Minutes
Pump Sentry - Protects Pump and OFF
P-8 Off
Compressor From Loss of Water ON = Select 100oF to 150oF
4 = Low
P-9 Display Brightness Control 13 = Maximum
13 = Maximum
o
F = Fahrenheit Displayed
P-10 Display oFahrenheit or oCentigrade o
F o
C = Centigrade Displayed
Cycle Pump With Compressor or OFF = Cycle OFF = Cycle With Compressor
P-11
Continuous Pump With Compressor ON = Continuous Pump
Reverse Fan Speeds During Heating nor = Normal Fan Operation
P-12 rEF = Reversed
Mode rEF = Reversed Fan in Heating
Continuous Fan or Cycle Fan With con = Continuous CYC = Cycle Fan w/Compressor
P-13
Compressor Fan Operation rEF = Reversed Fan In Heating
Reverse Cycle Heating or Electric
nor = Reverse Cycle Heating
Heat nor = Reverse
P-14
Only Option Installed (Cooling Only Cycle Heating
ELE = Electric Heater Installed
Units)
SP = Shade Pole Fan Motor
Fan Motor Type Selection - Shaded
P-15 SP = Shaded Pole SC = Split Cap. Fan Motor (NOTE: All
Pole or Split Capacitor Marvair® units use a split capacitor
motor. Select SC.)
Reset Memorized Programming
P-16 nor = Normal rSt = Reset Defaults
Defaults
Table 16. Programmable Parameters

Should any programming problems or confusion occur, reset the Memorized Default Settings by entering
the program mode and setting P-16 to rSt.

Marvair® Self-Contained and Split Systems Installation & Owner’s Manual 1/2011 Page 49 of 68
 Marvair® Reverse Cycle Air Conditioners
P-1 High Fan Limit
The upper fan speed limit can be changed to suit different motors and operating conditions. The high fan
limit is adjusted with the system installed and operational. The range of values are 56 through 85 and
represent arbitrary units. Setting a higher number, results in a higher fan speed, setting a lower number,
lowers the fan speed. Use the UP and DOWN arrow buttons to select the desired fan speed limit. The
factory default is eighty-five (85).

P-2 Low Fan Limit

The low fan limit determines the lowest output allowed for the low fan speed. The range of values for the
low fan speed are 30 through 55, in arbitrary units. Use the UP and DOWN arrow buttons to select the
desired low fan speed limit. Setting a higher number, results in a higher fan speed, setting a lower number,
lowers the low fan speed limit. The factory default setting is fifty (50).

Once the high and low fan speed limits are set, the unit will automatically readjust the four (4) remaining
fan speeds to produce six (6) equally spaced fan speeds in both the AUTO and MANUAL fan speed
modes.

P-3 Compressor Staging Time Delay

NOTE: This feature is not being used on the Marvair® reverse cycle air conditioners.

The compressor staging relay is provided for installations where more than one system is being operated
from the same power source. Setting the staging delays at different intervals allows only one compressor
to start at a time. The units should be staged at least five (5) seconds apart. The minimum delay is five (5)
seconds and the maximum is one hundred thirty-five (135) seconds. The factory default setting is fifteen
(15) seconds.

P-4 Temperature Calibration

Use this feature to calibrate the air sensor within a range of + ten (10)ºF. Enter the program mode and the
ambient temperature appears in the display. Use the UP and DOWN arrow buttons to select the desired
offset. The temperature in the display will increase or decrease according to the offset programmed.
The factory default setting is zero.

P-5 Fail-Safe Level

The system can be configured for one of four fail-safe levels. Selecting OFF turns off all fail-safe protection
and mnemonic display codes. Level ONE (1) shuts down the system, allows the system to restart after a
90 second delay and displays no failure code. Level TWO (2) shuts down the system but allows continual
restarts after the 90 second delay and displays the appropriate mnemonic failure code. Level THREE (3)
operates the same as level TWO (2) with the addition of a system shutdown after four (4) consecutive
failures. Manual reset is required to restart the system.

P-6 Low Voltage Cut-Off

The controller can be programmed to protect the system against sustained low AC line voltage conditions.
The compressor will be shut down and “LAC” flashed in the display if the line voltage goes below the
programmed value for more then ten (10) minutes. Programmable values are 75 VAC to 100 VAC for 120

Marvair® Self-Contained and Split Systems Installation & Owner’s Manual 1/2011 Page 50 of 68
 Marvair® Reverse Cycle Air Conditioners
volt units and 175 VAC to 200 VAC for 220 volt systems. The factory default is 85 VAC for 120 volt units
and 185 VAC for 220 volt systems. NOTE: Low Voltage Protection can be turned off by programming
OFF instead of selecting a voltage value.

P-7 De-Icing Cycle

The controller is equipped with a De-Icing Cycle to prevent ice build up on the evaporator coil during
extended periods of cooling operation. Installation variables such as grille sizes, length of ducting,
insulation “R” factors and ambient temperatures determine the cooling run time required to achieve the
set point. Customer usage may substantially increase run times by operating the system with the hatches
and doors open. Programming an unrealistic set point (55oF) and leaving the salon door open will usually
cause the evaporator to ice up on warm muggy days.

De-Icing is accomplished by switching the reversing valve into the HEAT mode while the system is
cooling. The valve will remain energized for the programmed cycle time. The cycle is programmable from
OFF through a period of 3 minutes. The factory default setting is OFF.

P-8 Optional Pump Sentry

The controller can be equipped with an optional temperature sensor that is used to monitor the heat
exchanger temperature. The sensor is plugged into the outside air sensor jack and programmed for a
temperature between 100 and 150ºF depending on water temperature and the system type. When the heat
exchanger temperature rise above the programmed value the pump and compressor are shut down and
“PPP” is flashed in the display. The factory default is OFF, no Pump Sentry installed.

P-9 Display Brightness Control

The display brightness can be adjusted to suit ambient cabin lighting conditions. The allowed settings are
four (4) to thirteen (13) the brightest. Typically a dark cabin will require a setting of four or five. A very
bright cabin will require a setting of twelve or thirteen. The factory default setting is thirteen (13).

P-10 Fahrenheit or Celsius Selection

The unit can be programmed to display either Fahrenheit or Celsius. Programming ºF displays degrees
Fahrenheit and programming ºC, displays degrees Celsius. The factory default setting is ºF, Fahrenheit.
When degrees Celsius (ºC) is selected the readings are displayed in tenths, i.e. 22.2ºC.

P-11 Cycle Pump With Compressor

To increase pump life and conserve electricity the pump can be programmed to cycle on and off with the
compressor. The pump can also be programmed to operate continuously whenever the system is on. To
program the pump for continuous operation, turn “P-11” ON. The factory default setting is OFF, which
cycles the pump with the compressor.

P-12 Reverse Automatic Fan Speeds During Heating

The automatic fan speeds can be reversed during the heating mode to improve heat output in cooler
climates. The fan speed is decreased as the temperature spread increases. The fan will speed up as the set
point is approached. Lowering the fan speed when the cabin is cold increases head pressure and raises the
supply air temperature. Increasing the fan speed as the set point is approached also reduces unnecessary
high pressure faults. The fan switches to low speed when the set point is satisfied and the compressor
Marvair® Self-Contained and Split Systems Installation & Owner’s Manual 1/2011 Page 51 of 68
 Marvair® Reverse Cycle Air Conditioners
cycles off. The fan can be programmed to operate the same as in cooling by programming “P-12” nor
which represents normal fan operation during reverse cycle heating. The factory default setting is rEF,
which reverses the automatic fan speeds during heating.

P-13 Cycle Fan With Compressor

The fan can be programmed to run continuously when the system is on or can be allowed to cycle with the
compressor. When cycled with the compressor, the fan will operate only when heating or cooling is called
or. To cycle the fan with the compressor select CYC which stands for cycle the fan with the compressor.
To operate the fan continuously select con which represents continuous fan operation. The factory default
setting is con continuous fan operation when the system is on.

P-14 Reverse Cycle or Electric Heat

Electric heat is not currently available on Marvair® units.

IMPORTANT
P-15 Fan Motor Selection
There are two basic fan motor types, shaded pole and split capacitor. Each motor reacts differently
to speed control and each motor requires different timing for optimum fan speed control. The default
setting is “SP” which selects the shaded pole motor type, however, “SC” should be selected if a split
capacitor type motor is used in the system. The Marvair® direct expansion systems are supplied with a
split capacitor type fan motor so “SC” should be selected. The factory default setting is “SP” for the
shaded pole type fan motor. IMPORTANT: The factory default setting “SP” should not be used on
the Marvair® reverse cycle air conditioners.

P-16 Reset Memorized Defaults

The default programming parameters can be reset by entering the program mode and selecting “rST”.
This will restore the programmable parameters to the values selected when the system was shipped.

Why Memorize New Defaults?

Once the desired programming changes have been made and the system tests satisfactorily, your work
can be saved as the new factory defaults. Your new defaults are initiated by simultaneously pressing
and releasing the UP and DOWN arrow buttons prior to exiting the program mode. New defaults can
be initialized at any time by entering the program mode and following the above instructions. Once new
defaults have been initialized the control will revert back to the new defaults whenever factory defaults
are restored as previously described in “P-16”.

Fail-Safe and Fault Handling Codes

When a fault is detected the controller will display one of the following Mnemonic fault codes:
HPF Indicates high Refrigerant pressure, 15 second delay, Ignored in HEAT mode.
LPF Indicates low Refrigerant pressure. There is a ten minute charge time delay.
LAC Indicates low AC line power
AAA Indicates failed air sensor. Unit will not run until repaired.
PPP Indicated the water pump has failed.

Marvair® Self-Contained and Split Systems Installation & Owner’s Manual 1/2011 Page 52 of 68
 Marvair® Reverse Cycle Air Conditioners
Fail-Safe
There are four levels of fail-safe protection including the fail-safe OFF mode. Level 1 monitors the
sensors, takes appropriate action and allows continuous restarts after a 90 second delay and does not
display the fault code. Level 2 works the same as Level 1, however, the appropriate fault code mnemonic
is displayed during the time-out between restarts. Level 3 is identical to Level 2 with the inclusion of a
three successive failures lockout routine. After four (4) consecutive failures the system is shutdown and a
manual reset is required.

Lockout
Lockout occurs if “P-5” is programmed for Level 3 and four consecutive faults are detected within a
heating or cooling cycle. Lockout causes the system to shut down and flash the mnemonic fault code.
Lockout can only be cleared by turning the unit OFF and then ON by using the POWER button.

Fault Display
When a fault occurs the appropriate mnemonic code is flashed in the display. The flashing mnemonic
can be removed from the display by pressing and releasing the POWER button to reset the controller.
Resetting the controller does not solve the problem caused by the fault.

Fail-Safe
Action Description of Action Taken
Level

FAIL-SAFE PROTECTION LEVELS TURNED OFF:

All Protection is Air Sensor Fault: Heating/Cooling Immediately Suspended; Normal
OFF Turned Off Operation Not Resumed Until Fault is Cleared. Air Sensor Fault
Code “Flashing Display” NO OTHER FAIL-SAFE PROTECTION IS
PROVIDED.

MINIMUM PROTECTION LEVEL

No Mnemonic Fault All Actions Taken in Fail-Safe Protection Level “0” Plus: In Addition,
1 Code Displayed Continuous 90 Second Compressor Restarts are Allowed.
Continuous 90Sec. FAULT Mnemonic CODE NOT DISPLAYED
Re-Starts Allowed ! NO OTHER FAIL-SAFE PROTECTION IS PROVIDED

Display Fault & Shut INTERMEDIATE PROTECTION LEVEL

Down Compressor All Actions Taken in Fail-Safe Protection Levels “0” & “1” Plus: In
2 With Continuous 90 Addition, The FAULT MNEMONIC CODE Message Will Be
Displayed With Continuous 90 Second Compressor Restarts
Second Delay Allowed.
Between Starts NO OTHER FAIL-SAFE PROTECTION IS PROVIDED

Display Fault and MAXIMUM PROTECTION LEVEL

Require Manual FAULT CODE MESSAGES ARE DISPLAYED and The Appropriate
3 Reset After 4 Action is Taken According to The Problem Encountered. After 4
Failures. Consecutive Failures Manual Reset is Required.

Table 17. Fail Safe Levels

Marvair® Self-Contained and Split Systems Installation & Owner’s Manual 1/2011 Page 53 of 68
 Marvair® Reverse Cycle Air Conditioners
Specification Notes
Custom cable lengths available on special request in 5 foot increments. Maximum length of display cable
is 50 feet. Sensor cable lengths should be limited to 50 feet. The outside air sensor, alternate air sensor
and condenser coil sensor are optional items and are not included with the standard control package.

Automated Factory Self Test Program

Self-Test Mode

The controller software contains a self-test program to facilitate factory testing of the entire air conditioning
system. Once the Self-Test mode is activated, the test cycle will continue until the AC power is interrupted
or the On/Off POWER button is pressed once which returns the system to the Off mode.

Activate the self-test mode by pressing and holding the On/Off POWER button while turning on the
AC power. Be sure to continue to hold the POWER button until the power on reset is completed. The
controller is now in the Self-Test mode.

Once activated the self-test software will continuously execute the following procedure:

1 - Turn on in the HEAT mode and supply heating for ten (10) minutes.

2 - Stop heating and run the fan only for five (5) minutes.

3 - Switch to COOL and continue cooling for ten (10) minutes.

4 - Stop cooling and run the fan only for five (5) minutes.

5 - Return to step one (1) and continue until interrupted.

The test mode will continue until the power is interrupted or the test is halted by pressing the On/Off
POWER button once.

Service Tools
Hour Meter
Total compressor cycle time is saved in EEPROM every 6 minutes of continuous compressor running
time. Cycles less than 6 minutes will be discarded to conserve memory and to allow for the most flexible
hour-meter possible.

To view the hour meter turn off the power at the AC breaker and hold the DOWN arrow button depressed.
While depressing the DOWN arrow button, restore AC power. After the power on reset routine is complete,
the following will appear on the display.
HOUR
METER THOUSANDS HOURS

H r 1 2 2 4

1. The hour meter mnemonic (Hr) is displayed for one (1) second.

Marvair® Self-Contained and Split Systems Installation & Owner’s Manual 1/2011 Page 54 of 68
 Marvair® Reverse Cycle Air Conditioners
2. The display blanks out for one second and then displays the THOUSANDS units for three (3)
seconds.

3. The display blanks out for one (1) second and then displays the hours for three (3) seconds.

4. The unit returns to the last operating state before power was removed.

The example shown is displaying twelve-hundred twenty-four (1,124) hours.

Maximum recorded time is 10,000 hours. The hour meter stops at the maximum (10,000 hrs) and can only
be reset by Marvair.

Service History
The controller will record and remember the last eight (8) service problems or service faults detected.
Each time a fault is detected, a one hour timer is started. During that hour the same recurring fault will
not be recorded. Should a different fault be detected during that hour, it will be entered into the service
history log.

The following events are entered into the service history log:

1. High Refrigerant Pressure

2. Low Refrigerant Pressure

3. Air Sensor Fault

4. Low AC Voltage

5. Pump or Loss of Water Fault

To view the service log, turn off the AC power and depress the MODE button. With the MODE button
depressed turn on the AC power. Once the power on reset is completed, the display will flash the most
recent mnemonic for the fault detected, followed by the event number. To view the other events detected
press either the UP or DOWN arrow buttons.

To exit the service history log press the POWER or the MODE button or wait 30 seconds without
pressing any buttons.

The service log can be cleared by simultaneously pressing the POWER and DOWN arrow buttons while
you are viewing the service log mode.

Double check all electrical connections and all hose connections.

Marvair® Self-Contained and Split Systems Installation & Owner’s Manual 1/2011 Page 55 of 68
 Marvair® Reverse Cycle Air Conditioners

Figure 10. MachAir I Electrical Schematic

Marvair® Self-Contained and Split Systems Installation & Owner’s Manual 1/2011 Page 56 of 68
 Marvair® Reverse Cycle Air Conditioners
Chapter 6 – Start-Up

Cooling Cycle
1. Turn the seacock valve to the open position.
2. There is a short delay on starting. On SPM models, set the delay to 15 seconds. If there is more than
one unit, set the delays to different times.
3. If the water pump has a dedicated breaker, turn it on. Verify that water is being discharged
overboard.
4. Turn on the circuit breaker to the Marvair® unit.
5. Refer to the operating instructions in this manual for your thermostat/controller and set the system for
cooling by using the display module or the thermostat.
6. Adjust the cooling temperature set point on the display module or the thermostat higher than the cabin
temperature.
7. Slowly lower the thermostat’s cooling set point until the set point is below the cabin temperature. The
blower, compressor and pump should be operating.
8. Close all doors and hatches.
9. Allow the unit to operate 10 minutes.
10. After 10 minutes, there should be a 15°F (8°C) to 20°F (9°C) difference in the supply and return air
temperatures.

Heating Cycle
Note: Do not turn unit “OFF” and then immediately back “ON”. Wait three minutes to allow
refrigerant pressures to equalize.
1. Follow steps 1, 2, 3, & 4 as outlined above in the Cooling Cycle section.
2. Refer to the operating instructions in the manual & set the system for heating by using the display
module or the thermostat.
3. Adjust the heating temperature set point on the display module or the thermostat lower than the cabin’s
temperature.
4. Slowly raise the thermostat’s heating set point until the set point is above the cabin temperature. The
blower, compressor and pump should be operating.
5. Close all doors and hatches.
6. Allow the unit to operate 5 minutes.
7. After 5 minutes there should be a 15°F (8°C) to 25°F (9°C) difference in the supply and return air
temperature.

Marvair® Self-Contained and Split Systems Installation & Owner’s Manual 1/2011 Page 57 of 68
 Marvair® Reverse Cycle Air Conditioners
Operation Checklist
1. Verify that all tie downs clamps have been correctly installed
2. Make sure all electrical cover plates are in place
3. Test for continuity between the ground and the boat’s bonding system or the engine’s DC negative
connection
4. Make sure that there are zero volts between the boat’s ground and the ground in the SeaMach reverse
cycle air conditioner with the unit operating.
5. Check all water hoses for leaks.
6. Make certain that poisonous gases or noxious fumes are NOT being introduced into the vessel via the
HVAC system.
7. Check for proper condensate drainage.

Chapter 7 - Winterizing the System

There are two scenarios for winterizing the system – the boat remains in the water or the boat is
out of the water, in dry dock storage. Please follow the procedures described below for your situation.

Boat remains in the water

In water storage requires the use of a potable anti-freeze solution throughout the system’s water supply
and discharge lines. Be sure to follow all state, local and federal ordinances before discharging an anti-
freeze solution overboard.
1. Close ball valve.
2. Disconnect water line at ball valve.
3. Insert line into a bucket of potable anti-freeze.
4. Run air conditioner until a solid stream of anti-freeze is being discharged overboard.
5. Reconnect water line at ball valve.

Boat is out of water in dry dock

With the boat out of the water:
1. Open the seacock to permit all the water to drain out of system via the thru-hull fitting.
2. Remove and empty the seawater strainer basin.
3. Loosen the screws on the pump head to allow the water to drain from the pump and from the water line
between the pump and strainer.
4. Close the seacock.

When the boat is put back into the water in the spring:
1. Gradually open the seacock to allow water to fill the system to the level of the pump.
2. Tighten the pump face to achieve a seal.
3. When pump is primed, open the seacock valve completely.

Marvair® Self-Contained and Split Systems Installation & Owner’s Manual 1/2011 Page 58 of 68
 Marvair® Reverse Cycle Air Conditioners
Chapter 8 – Troubleshooting

WARNING
Troubleshooting and repair of the Marvair® unit should only be performed by qualified personnel.

Troubleshooting Guide
PROBLEM/SYMPTOM LIKELY CAUSE(S) CORRECTION
The unit does not 1. Power supply problem. 1. Check voltage at power supply and at the
operate. (nothing electrical box. Check wiring to unit and at shore,
works a all) boat and unit (if applicable) breakers or fuses.
Check shore power connection.
2. Tripped breaker/disconnect. 2. Check circuit protection devices for continuity.
3. Display/Controller. 3. Setpoint may be too high if in cooling mode or
too low if in heating mode; check unit and reset.
Display/Controller may be out of calibration
or otherwise defective. Also check for loose
connection(s).
4. Low Voltage. 4. Check voltage at dock. Check panel voltage.
Check shore connections and shore cord.
Check voltage at board in the unit. If low, check
wiring connections.
Unit has power, but 1. Check interface cable 1. Replace
display/controller is connections.
inactive. Control is faulty.
Blower runs but 1. Power supply problem. 1. Check voltage at power supply. Voltage at unit
compressor does not must be within 10% of rated nameplate voltage.
start. 2. Display/Controller. 2. Check the display/controller and unit for loose
wires. Secure any loose connection. Fan is
programmed to run with the compressor. Adjust
set points or reset defaults. Check location of
sensor and make sure that it does not touch the
indoor coil. The sensor and/or thermostat should
be replaced if defective.
3. Safety switches are 3. Check for water flow. Check for proper air flow.
tripping out unit. Check refrigerant charge. Check switches for
loose wire connection, broken or burned contacts.

4. Loose or defective 4. Tug on wires to see if they will separate from their
wires. connections. Replace terminals if they are loose
or weak.

Marvair® Self-Contained and Split Systems Installation & Owner’s Manual 1/2011 Page 59 of 68
 Marvair® Reverse Cycle Air Conditioners
PROBLEM/SYMPTOM LIKELY CAUSE(S) CORRECTION
Blower runs but 5. Compressor. 5. Check for power to compressor on PC board.
compressor does not Check for electrical shorts, ground and open
start. circuits. Check for electrical shorts, ground and
(continued) open circuits. Replace compressor if defective. If
electrical checks are ok, install a start capacitor
and direct wire to see if the compressor will start.
If this fails, remove and replace the compressor.
6. Refrigerant leakage or 6. Locate leak(s), reclaim, repair, evacuate and
loss. recharge unit with refrigerant.
7. Control board. 7. Verify that power is being provided from the
control board. Replace control board if it is
defective.
8. Compressor Run 8. Verify capacitance, check for electrical shorts and
Capacitor. ground. If defective, replace.
Compressor runs, but 1. Blower motor capacitor. 1. Verify capacitance, check for electrical shorts and
blower will not run. ground. If defective, replace.
2. Blower motor. 2. Check for electrical shorts, ground and open
circuits. Replace blower motor if it is defective.
3. Power supply problem. 3. Check voltage at power supply. Voltage at unit
must be within 10% of rated nameplate voltage.
4. Control board. 4. Verify that power is being provided from the
control board. Replace control board if it is
defective.
Display/controller 1. No power to reversing 1. Check wiring to valve. Replace valve if defective.
calling for heating and valve or bad valve.
unit is in cooling mode.
Unit trips off on high 1. Low water flow to the 1. Check water lines to the unit for kinks in line.
pressure in cooling condenser. Check strainer and thru hull for obstructions.
mode or low pressure Clean as required.
in the heating mode, Verify seacock (ball valve) is open. Check for
but pump is running. obstruction in the pump and remove.
2. Pump is air locked. 2. Purge air from system
Pump does not run. 1. Compressor is off 1. Adjust set point.
and the pump is
programmed to run with
the compressor.
2. If there is a pump relay, 2. Reset breaker.
check pump circuit
breaker.
3. No power to pump at 3.Control board may be faulty.
control board.
4. Faulty pump.1 4. Replace pump.

Marvair® Self-Contained and Split Systems Installation & Owner’s Manual 1/2011 Page 60 of 68
 Marvair® Reverse Cycle Air Conditioners
PROBLEM/SYMPTOM LIKELY CAUSE(S) CORRECTION
Low air flow. 1. Dirty filter. 1. Clean filter.
2. Return air flow blocked. 2. Remove obstruction.
3. Louvers in grille closed. 3. Open louvers.
4. Fan speed set too low. 4. Raise fan speed and reset program parameters.
Low Water Flow1 1. Restriction or blockage 1. Clean raw water strainer. Clean thru hull. Make
in waterline. sure valve is open. Clean pump.
2. Air lock in pump 2. Open ball valve, remove discharge hose and
open valve to bleed air from the pump. Check
pump’s impellor for wear or debris.
Unit provides 1. Restriction in water 1. Strainer or thru-hull fitting are clogged. Clean and
insufficient cooling. system. check for water flow. Make sure seacock (ball
valve) is open.
2. Water pump. 2. Check for electrical shorts, ground and open
circuits. Replace water pump if it is defective.
Replace water pump if it is undersized.
3. Air filter. 3. Clean or replace the air filter if it is dirty.
4. Indoor coil. 4. The indoor coil may require cleaning if the unit
was operated without a filter.
5. Ice on indoor coil. 5. Thermostat setting is too low. Shut down unit until
ice has melted and restart at a higher temperature
setting. Check to see if filter is dirty or long or
restricted ductwork.
6. Unit is undersized 6. Check if the unit is undersized for the load.
Replace with larger unit or add additional unit(s) if
necessary.
7.Low refrigerant 7. Add refrigerant
Unit provides 1. Restriction in water 1. Strainer or thru-hull fitting are clogged. Clean and
insufficient heating. system. check for water flow. Make sure seacock (ball
valve) is open.
2. Water pump. 2. Check for electrical shorts, ground and
open circuits. Replace water pump if it is defective
or undersized.
3. Air filter. 3. Clean or replace the air filter if it is dirty.
4. Indoor coil. 4. The indoor coil may require cleaning if the unit
was operated without a filter.
5. Unit is undersized. 5. Check if the unit is undersized for the load.
Replace with larger unit or add additional unit(s) if
necessary.
6. Water temperature. 6. Check water inlet temperature using a
thermometer. Low inlet water temperatures, less
than 50°F (10°C), combined with high heating
set points and restricted air flow can cause low
pressure trips. Check heating set point and air
flow.
Marvair® Self-Contained and Split Systems Installation & Owner’s Manual 1/2011 Page 61 of 68
 Marvair® Reverse Cycle Air Conditioners
PROBLEM/SYMPTOM LIKELY CAUSE(S) CORRECTION
Unit provides 7. Reversing valve. 7. Check for power to the solenoid coil, verify that
insufficient heating. the coil is functional. If the unit still does not switch
(continued) to heating, replace the reversing valve, evacuate
and recharge the unit.
8. Low refrigerant 8. Add refrigerant
Noise operation. 1. Copper tubing is 1. Adjust by bending slightly to a more stable
vibrating. position. Separate any tubing that is making
contact with other tubing or components.
2. Indoor blower assembly. 2. If blower wheel is hitting housing, adjust the wheel
position in the housing. Replace blower motor or
assembly if the bearing(s) are defective.
3. Loose cabinet or 3. Check and tighten loose screws.
components.
4. Improper unit 4. Make sure unit is level and secure to deck.
installation.
Water is leaking from 1. Condensate pan. 1. Check for leaks and repair as required.
unit. 2. Condensate drain line 2. Check for leaks and repair as required.
or pump.

3. Loose fittings or 3. Tighten fittings and connections. Check the

connections. condensate drain line for leaks.
Electrical shock at unit. 1. Electrical component is 1. Check control board, blower motor, compressor
shorted to ground. and pumps with an ohmmeter or high potential
tester. Determine what is grounded and replace or
rewire.
2. Line trip is too sensitive

1
Cal pumps are built with an auto-reset thermal breaker to minimize the chance for motor burn out. If water flow
is too low, the pump will turn off until it cools down. Do not assume that the pump is defective. Check the pump
by feeling the pump housing to determine if it is on or turned off due to the protective thermal shut down. If the
pump is running or very hot – more than 40°F higher than the surrounding air temperature- investigate the other
reasons for low water flow. If the pump is not running and cool to the touch, check for power to the pump.

Marvair® Self-Contained and Split Systems Installation & Owner’s Manual 1/2011 Page 62 of 68
 Marvair® Reverse Cycle Air Conditioners
Alarm Screens
A complete description of the alarm screens can be found in the section that describes the display/controller
for your Marvair Marine unit. A high pressure alarm when in the cooling mode or a low pressure alarm in
the heating mode is typically caused by a lack of water flow. A low pressure alarm when the unit is in the
cooling mode or a high pressure alarm when the unit is in the heating mode typically means that the there
is insufficient air flow. Refer to the Troubleshooting table for diagnosing and correcting these problems.

Fault Mode of Operaion Likely Cause

High Pressure Alarm Cooling Low Water Flow
Low Pressure Alarm Cooling Inadequate Air Flow
High Pressure Alarm Heating Inadequate Air Flow
Low Pressure Alarm Heating Low Water Flow
Table 18. Alarm Faults

Chapter 9 – Warranty

Marvair® Marine Self-Contained and Split Systems Warranty

Parts
If any part of your Marvair® unit fails because of a manufacturing defect within twenty-four months
from the date of purchase of a new boat or within twenty-four months from the date of installation of the
air conditioner, but not to exceed thirty-six from the date of manufacture by Marvair, Marvair will furnish
without charge, EXW Cordele, Georgia, the required replacement part.
Labor
If any part of your Marvair® reverse cycle air conditioner fails because of a manufacturing defect
within twenty-four months from the date of purchase of a new boat or within twenty-four months from
the date of installation of the air conditioner, but not to exceed thirty-six from the date of manufacture by
Marvair, Marvair will pay for the related service labor to replace the failed part according to the Marvair
Flat Rate Schedule currently in effect. The owner must provide proof of the date of the purchase of the boat
or date of installation of the Marvair® unit. The owner’s registration card filed with Marvair, the invoice
for the purchase of the vessel, an invoice for the installation of the Marvair® unit, or similar documents
are examples of proof of the date.
When service is required, it must be performed during normal working hours (8:00 a.m. to 5:00
p.m.) Monday through Friday and must be performed by Marvair personnel or their designated Service
Representative.
The responsibility of the Owner of the Equipment includes the following:
1. To operate the equipment according to the manufacturer’s instructions.
2. To provide easy accessibility for service.
3. To check and reset circuit breaker(s) and disconnect before calling for service. (Circuit
breaker(s) may be in the main service panel.)
4. To keep the unit clean and free of dirt.
5. To clean and/or replace the filter as required. (The filter may be located in the return air filter
grille or in front of the evaporator coil.)
Marvair® Self-Contained and Split Systems Installation & Owner’s Manual 1/2011 Page 63 of 68
 Marvair® Reverse Cycle Air Conditioners
6. To keep the evaporator coil clean and the condenser coil free of sediment or scale.
7. To pay the charges incurred when any of the above have not been done.
8. To pay for repair or replacement of any material or part other than those within the Marvair
unit or thermostat itself.
9. To check any fuses on the circuit board and replace as required.

The owner of the product may ship the allegedly defective or malfunctioning product or part to Marvair,
at such owner’s expense, and Marvair will diagnose the defect and, if the defect is covered under this
warranty, Marvair will honor its warranty and furnish the required replacement part. All costs for shipment
and risk of loss during shipment of the product or part to Marvair and back to the owner shall be the
responsibility and liability of the owner. Upon request by an owner, Marvair may arrange for remote
diagnosis and repair of the allegedly defective or malfunctioning product or part.
An owner requesting performance under this Warranty shall provide reasonable access to the allegedly
defective or malfunctioning product to Marvair and its authorized agents and employees.
This warranty does not cover damage caused by improper installation including any refrigerant leaks
in the tubing and fittings between the evaporator and condenser sections on split systems; misuse of
equipment; negligent servicing; damage due to use of the product for purposes other than those for which
it was designed; damage caused by natural disasters, power surges, lightning and submersion; damage
caused by unauthorized modifications; and damage caused by improper wiring or power supply to the air
conditioner including operating the unit with an undersized generator.
THIS WARRANTY AND SERVICE POLICY CONSTITUTE THE EXCLUSIVE REMEDY
OF ANY PURCHASER OF A MARVAIR REVERSE CYCLE AIR CONDITIONER AND IS IN
LIEU OF ALL OTHER WARRANTIES, EXPRESSED OR IMPLIED, INCLUDING, WITHOUT
LIMITATION, ANY IMPLIED WARRANTY OF MERCHANTABILITY OR FITNESS FOR USE,
TO THE FULLEST EXTENT PERMITTED BY LAW. IN NO EVENT SHALL ANY IMPLIED
WARRANTY OF MERCHANTABILITY OR FITNESS FOR USE EXCEED THE TERMS
OF THE APPLICABLE WARRANTY STATED ABOVE AND MARVAIR SHALL HAVE NO
OTHER OBLIGATION OR LIABILITY. IN NO EVENT SHALL MARVAIR BE LIABLE FOR
INCIDENTAL OR CONSEQUENTIAL DAMAGES OR MONETARY DAMAGES.
THIS WARRANTY GIVES YOU SPECIFIC LEGAL RIGHTS, AND YOU MAY ALSO HAVE OTHER
RIGHTS WHICH VARY FROM STATE-TO-STATE. Some states do not allow limitations or exclusions,
so the above limitations and exclusions may not apply to you.
8/07 Rev. 4

Marvair® Self-Contained and Split Systems Installation & Owner’s Manual 1/2011 Page 64 of 68
 Marvair® Reverse Cycle Air Conditioners

Appendix A - Dimensional Drawings

MAB 07-16 Dimensional Drawings

<I> <L> <M>

<K>

<H>

<F> <N> Oval

<J>
<G> Hose
Ring

<B>

<C>

<E>
<A>
<D>

A B C D E F G H I J K L M N Part # Description
INCH 24 13 5/8 4 1/2 11 5 1/2 2 7/8 4 11/16 6 2.6 5 1/2 2.66 7 5/9 2 5/8 6 1/8
MAB07 91565 5’’ OVAL RING
MM 610 346 114 279 140 73 119 152 66 140 68 191 67 156
INCH 24 13 5/8 4 1/2 11 5 1/2 2 7/8 4 11/16 6 2 5/8 5 1/2 2 11/16 7 5/9 3 7 1/4
MAB10 91566 6’’ OVAL RING
MM 610 346 114 279 140 73 119 152 67 140 68 191 76 184
INCH 25 13 7/8 4 1/2 11 5 1/2 2 7/8 4 11/16 6 2 5/8 5 1/2 2 11/16 7 5/9 3 7 1/4
MAB12 91566 6’’ OVAL RING
MM 635 352 114 279 140 73 119 152 67 140 68 191 76 184
INCH 25 13 7/8 4 1/2 11 5 1/2 2 7/8 4 11/16 6 2 5/8 5 1/2 2 11/16 7 5/9 3 7/16 8 3/4
MAB16 91567 7’’ OVAL RING
MM 635 352 114 279 140 73 119 152 67 140 68 191 87 222

Marvair® Self-Contained and Split Systems Installation & Owner’s Manual 1/2011 Page 65 of 68
 Marvair® Reverse Cycle Air Conditioners
MAB 24 Dimensional Drawings
FILTER CONTROL BOX

COIL

16 13/16 [426.88]
COIL

BLOWER BOX COMPRESSOR

WRAP
18 [457.09]

29 3/16 [740.63]
8 3/4" (19.050 MM) X 3 1/4" (6.350 MM)
OVAL ADAPTER (TYP.)

WATER OUT

MARVAIR

14 9/16 [369.70]

16 13/16 [426.92]

CONTROL
WATER IN
BOX 1 [25.92]

14 [356.26] CONTROL BOX

CONDENSATE FITTING
.563 O.D.
(14.2 MM)
(TYP.)

HEAT EXCHANGER CONTROL BOX

WATER OUT 5 7/8 [149.25] 2 11/16 [68.43]
A
A MARVAIR

10 1/8 [256.44]
B B

WATER IN LEFT SIDE FRONT VIEW RIGHT SIDE

VIEW VIEW

HEAT EXCHANGER
BUSHING SCHEDULE
Mk QTY O.D.
Mk QTY I.D.
WATER
IN 5/8" A 2 15/16"
WATER B 4 11/16"
OUT 5/8"

Marvair® Self-Contained and Split Systems Installation & Owner’s Manual 1/2011 Page 66 of 68
 Marvair® Reverse Cycle Air Conditioners
Appendix B - Wiring Diagrams

Marvair® Self-Contained and Split Systems Installation & Owner’s Manual 1/2011 Page 67 of 68
 Marvair® Reverse Cycle Air Conditioners
Notes

Marvair® Self-Contained and Split Systems Installation & Owner’s Manual 1/2011 Page 68 of 68