CTM CT Instruction Manual

MARINE
SELF-CONTAINED
AIR CONDITIONER
CT Models
(6,000 / 10,000 / 12,000 / 16,000 BTU)
INSTALLATION & USER MANUAL
Form No. UM-CT08272021
CTM-MARINE
+1 (800) 766 - 5256
[email protected]
www.ctm-marine.com
WARNING
Cancer and reproductive Harm
www.P65warnings.ca.gov
Please visit http://ctm-marine.com/user-manual/
for the most updated version of this manual.
Follow each one of the steps as explained on this manual, any deviation from the procedure explained herein constitutes improper installation of the unit and therefore waives and
forever discharges CTM Marine and its subsidiaries from any liability in connection to the installation; use; and functioning of the unit and any and all systems and parts connected to it.

CTM Marine Self-Contained CT Installation & User Manual
2
Unit Label Information ………….……..………………………………………………………………….… 3
Warning Labels …………………………………………………………………………………………….… 4
How To Read This Manual ………………………………………………………………………………….. 5
Product Description & Features ……………………………………………………………………………. 7
Technical Data …………………………………………………………………………………………. 8
Installation Overview ……………………………………………………………………………………… 10
Unit Installation …………………………………………………………………………………………….. 11
Locating the Unit ……………………………………………………………………………………..… 11
Blower Rotation ……………………………………………………………………………………….... 11
Non-slip Isolation Vibration Tape …………………………………………………………………….. 12
Mounting Brackets …………………………………………………………………………………….. 12
Condensate Drains …………………………………………………………………………….…..….. 12
Ducting ……………………………………………………………………………………………………… 13
Seawater System ……….…………………………………….……………..…………………………..…14
Electrical Connections ………………………………………………………………………………….… 15
Display/Control Compatibility …………………………………………………………………….…….. 18
Troubleshooting ……….……………………………………………………………………………..….… 19
CTM LIMITED NON-TRANSFERABLE WARRANTY ……….……………………………………….… 22

CTM Marine Self-Contained CT Installation & User Manual
3
Unit Label information
NOTES:
How To Read Your Label
*Unit label data changes by model
S = Unit With Soft Start
H = 208 - 240 V Unit
HS = 208 - 240 V Unit
With Soft Start
Vessel’s water pump
minimum requirement
Factory Refrigerant
Charge

CTM Marine Self-Contained CT Installation & User Manual
4
WARNING
THIS AIR CONDITIONER UNIT, INCLUDING DUCT
WORK, MUST NOT BE INSTALLED IN A FUEL VAPOR
AREA OR ENGINE ROOM WHERE ANY POSSIBILITY
OF FUEL VAPOR, ENGINE EXHAUST OR ANY
OTHER TOXIC GASES MAY EXIST, THIS UNIT IS
NOT VAPOR PROOF AND COULD INTRODUCE
DEADLY GASED INTO THE LIVING SPACE IF
IMPROPERLY INSTALLED. THIS COULD LEAD TO
DEATH OR DISABILITY OF THE OCCUPANTS. SEE
OWNNER'S MANUAL.
ELECTRICAL SHOCK HAZARD
DISCONNECT VOLTAGE AT MAIN PANEL
OR POWER SOURCE INLET BEFORE
OPENING ANY COVER
FAILURE TO COMPLY WILL RESULT IN
INJURY OR DEATH
DANGER
CAUTION!
HIGH COMPRESSOR
TEMPERATURE IS NORMAL
DO NOT TOUCH
R410A
REFRIGERANT
Type of Refrigerant
Warning Labels
Follow each one of the steps as explained on this manual, any deviation from the procedure
explained herein constitutes improper installation of the unit and therefore waives and forever
discharges CTM Marine and its subsidiaries from any liability in connection to the installation;
use; and functioning of the unit and any and all systems and parts connected to it.
WARNING
Cancer and reproductive Harm
www.P65warnings.ca.gov

CTM Marine Self-Contained CT Installation & User Manual
5
Please carefully read and follow all safety information and instructions before installing your unit. You
may always contact Customer Service at [email protected] if you have any doubts, concerns, or
questions in connection to your unit or to this Instructions Manual.
NOTICE: Failure to strictly follow these warnings and instructions may result in malfunction of the
product, death or serious injury.
CTM Marine does not accept any liability for damage in case of:
>Failure to assemble or connect the unit properly following the instructions in this manual.
>Damage to the unit and its accessories resulting from mechanical inuences and excess voltage.
>Any alteration to the units.
>Use for purposes other than the purposes described in this manual.
In the interest of product improvement, the specications and design are subject to change without prior
notice.
How To Read This Manual
This manual provides proper installation information of CTM-Marine self-contained air conditioning units.
Improper installation procedures can result in unsatisfactory performance and/or premature failure of these
a/c units as well as serious injury or death. Before proceeding, please read this manual completely. Follow
each one of the steps as explained on this manual, any deviation from the procedure explained herein
constitutes improper installation of the unit and therefore waives and forever discharges CTM Marine from
any liability in connection to the installation; use; and functioning of the unit and any and all systems and
parts connected to it.
Throughout this manual you will nd a few signaling symbols. Please take a time to read and understand
what each signaling symbol means:
!Used to indicate a dangerous situation where, if not followed
carefully, could result in serious injury or death.
Used to indicate important and useful information.
Used to indicate additional information.
QR Code for access to virtual content such as tutorial videos.

CTM Marine Self-Contained CT Installation & User Manual
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Some sections of this instructions
manual have QR codes that you can
easily scan with your Smartphone. They
generally contain tutorial videos
following the instructions in this manual
or additional information.
Pay attention to signaling symbols
throughout this manual with important
information.
Refer to the illustrations throughout
this manual for guidance.
Some pages have a boxed section on
the right to indicate potential physical
injury hazards and potential damages
to the units. It's important to read,
understand and obey safety
instructions.

CTM Marine Self-Contained CT Installation & User Manual
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Product Description & Features
Thank you for purchasing our CTM Marine self-contained marine air conditioner. The CTM Marine
CT series are self-contained, direct-expansion, seawater cooled, reverse cycle air conditioners
designed for marine applications.
The CTM Marine self-contained marine air conditioner works by removing heat and moisture from
the cabin, which lowers the temperature and the humidity levels. At the same time conditioned air
is blown through the ducting system.
The blower fan draws warm humid air from the cabin across the evaporator where the heat from
the air is transferred to the refrigerant in the evaporator coil. The refrigerant then evaporates and
transforms from liquid to gas, absorbing the heat from the cabin air.
The compressor compresses the refrigerant gas and pumps it through the condenser coil. Seawater
is circulated through the inner tube in the condenser coil by the seawater pump which cools the
refrigerant and condenses into a liquid.
The heat absorbed by the evaporator in the refrigerant is then exchanged to the seawater and
discharged overboard. The liquid refrigerant is then passed through the evaporator coil again to
repeat the cycle.
The same process occurs for reverse-cycle heating, but backwards. The refrigerant ows in the
opposite direction through the reversing valve and heat is transferred from the seawater in the
condenser coil to the refrigerant and then to the air blowing through the evaporator.
Water temperature is crucial for the CTM Marine air conditioners to function properly. The system
will operate most efciently in temperatures below 90ºF (32ºC) when cooling, and above 55ºF
(13ºC) when heating. The unit will operate at higher or lower seawater temperatures, but at a
reduced capacity. However, when seawater temperatures drop below 40ºF (5ºC) the system
operates at around 50% capacity. Anything below those temperatures will not work since the
pressure in the system will be so low that the unit will shut down in consequence a low-pressure
fault.
Refrain from altering the unit. Any alteration may cause malfunction, serious injury or deth. This unit
contains electric and heat connectors and sources. Alteration to any part of this unit may cause
exposure to toxic or harmful elements.

1. Duct Ring
2. Blower/Fan
3. Condenser Coil
A. Outow
B. Inow
4. Blower/Fan Plate
5. Evaporator
6. Air Filter
7. Compressor
8. Reverse Valve
9. Stainless Steel Base
10. Drain Pan
11. Drain Holes
12. Electrical Box Back Plate
13. Capacitor
14. U-Board
15. Electrical Box Cover
1
1
2
3
4
5
6
2
3
A
A
B
8
B
4
5
6
7
7
8
9
9
11
11
11
12
10
10
13
14
15

CTM Marine Self-Contained CT Installation & User Manual
9
W D
H
E
Model No. CT-6 CT-6H CT-10 CT-10H CT-12 CT-12H CT-16 CT-16H
Capacity (BTU) 6,000 10,000 12,000 16,000
Voltage (V) 100-120 208-240 100-120 208-240 100-120 208-240 100-120 208-240
Cycle (Hz) / Phase (Ph) 50-60 / 1
Input: Cool (A) 4.5 2.1 6.7 3.3 8.7 4.3 10.5 5.1
Input: Heat (A) 5.6 2.7 8.8 3.9 10.8 4.9 13.5 6.6
Fuse Max/Min (A) 15/10 10/7 25/16 15/10 25/16 15/10 40/25 20/13
Locked Rotator Amps (A) 35 15 42 22 43 23 60 34
Seawater Inlet Connection (in/mm) 5/8 / 16
Seawater Outlet Connection (in/mm) 5/8 / 16
Seawater Flow (GPH) 150 250 250 500
Refrigerant Type R410A
Net Weight (lbs/Kg) 41 / 18.60 50 / 22.7 57 / 25.90
Width (W) in/mm 15.28 / 388 20 / 508
Height (H) in/mm 11.50 / 292 13.25 / 337 14 / 356
Depth (D) in/mm 9.50 / 240 12 / 305 13.5 / 343
Duct Ring (E) in/mm 4 / 100 5 / 127 6 / 152
Min. Return Air Grille (sq in / sq cm) 64 / 413 100 / 646 130 / 839 160 / 1033
Min. Supply Air Grille (sq in / sq cm) 32 / 206 60 / 388 70 / 452 80 / 517

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Installation Overview
Supply Air Grille
Display Control
A/C Electrical Box
Overboard Discharge
Water Line
Water Line
Thru-Hull Inlet
Shut-Off Valve
Under the water line
Above the water line
Strainer
Pump
Coil Inow Hose
A/C Unit
Condensate
Drain
Hose
Condensate
Drain
Hose
Insulated
Duct
Coil Outow Hose
Return Air
Grille
!
!
Follow each one of the steps as explained on this manual, any deviation from the procedure
explained herein constitutes improper installation of the unit and therefore waives and forever
discharges CTM Marine and its subsidiaries from any liability in connection to the installation;
use; and functioning of the unit and any and all systems and parts connected to it.

!
!
CTM Marine Self-Contained CT Installation & User Manual
11
Read these instructions completely and then plan all connections which must be made to the a/c unit including ducting,
condensate drain line, seawater inlet and outlet hoses, electrical power connection, location of control, and seawater pump
placement, to assure easy access for routing and future servicing.
NOTICE: 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. Follow
all safety codes. Wear safety glasses and work gloves and place a re extinguisher close to the work area. If you have questions,
contact CTM Marine: customer service representatives are available to answer questions. Installing parts on maritime equipment
requires knowledge on handling tools and marine qeuipment. If you are not sure whether or not you possess the skills CTM
Marine recommends consulting with a professional before engaging on self-help.
Locating The Unit
Mount unit with condenser/evaporator coil directly behind return air grill
or with at least 3" (76mm) of air circulation clearance if adjacent to a
bulkhead or other obstructions. See Figure 1. Compressor should be
mounted away from return air grill if possible to minimize sound level in
cabin (Sound Covers are optional.
Blower Rotation
If needed, loosen the lock screw on the blower, and secure the screw
tightly once the blower is adjusted at the optimal position with the most
direct airow discharge. See gure 2.
>The a/c unit must be mounted
to a low at level surface, in
bottom of locker, under a bunk or
dinette seat, or in a similar location.
Failure to obey these installation notices
could result in damage to the unit.
>To ensure proper airow, allow a
minimum clearance of 3 in. (76 mm) in
front of the evaporator, and a minimum
clearance of 4 in. (102 mm) in front of the
return air grille.
CARBON MONOXIDE HAZARD
>Never install your air conditioner
in the bilge or engine room areas.
If you have any questions or
concerns call CTM Marine
customer service.
Make sure that the selected location is
sealed from direct access to bilge and/or
engine room vapors. Do not terminate
condensate drain line within three feet (91
cm) of any outlet of engine or generator
exhaust systems, nor in a compartment
housing an engine or generator, nor in a
bilge, unless the drain is connected
properly to a sealed condensate or
shower sump pump.
>The a/c unit should never be placed
such that it can circulate carbon
monoxide, fuel vapors or other noxiou
s fumes into the boat’s living spaces. Do
not install or operate a self-contained unit
in the engine room or near an internal
combustion engine. Failure to follow this
precaution could result in serious injury or
death.
Unit Installation
EXPLOSION HAZARD
>Self-contained units do not
meet federal requirements for ignition
protection. Do not install in spaces
containing gasoline engines, tanks,
LPG/CPG cylinders, regulators, valves
or fuel line ttings. Failure to
comply may result in injury or death. If you
have an emergency or feel unsafe fue to
re hazards during the installatin, call 911
immediately.
FIGURE 1
Return Air Grill
Airow
4.0 (102mm) inch minimum clearance in front of return air grill
3.0 inch (76 mm) minimum clearance in front of condenser
Bulkhead Airow
Return Air Grill
FIGURE 2
1. Loosen adjustment screw
2. Rotate the blower to desired position
3. Tighten the adjustment screw
Follow each one of the steps as explained on this manual, any deviation from the procedure
explained herein constitutes improper installation of the unit and therefore waives and forever
discharges CTM Marine and its subsidiaries from any liability in connection to the installation;
use; and functioning of the unit and any and all systems and parts connected to it.
!

CTM Marine Self-Contained CT Installation & User Manual
12
Base Pan
Figure 4
Mounting Bracket Mounting Brackets
Base Pan
Mounting Bracket Mounting Brackets
Figure 3
Non-Slip Isolation Tape
Attached To Base Pan
Figure 5
5/8" Marine Grade Reinforced Hose
Stainless Steel Hose Clamp
5/8" Hose Barb
Base Drain Pan
Thread Seal Tape
Non-Slip Isolation Vibration Tape
Your a/c unit comes with a separate non-slip isolator tape design to dampen the vibration caused by
the operating a/c unit. Proceed to place the tape on the base of the A/C unit securely. See gure 3.
Condensate Drains
Place the 2 hose barbs (supplied) in their respective drain holes on the base pan. Secure the drain
hose with a stainless steel hose clamp. Route drain hose to a proper collection point. See gure 5.
!
Once this tape is installed care must be taken when moving the a/c unit across mounting surfaces as
the tape can be damaged if excessive dragging occurs.
CARBON MONOXIDE HAZARD
Do not terminate condensate drain lines within three feet (91 cm) of any outlet of engine or generator exhaust
systems, nor in a compartment housing an engine or generator, nor in a bilge, unless the drain is connected
properly to a sealed condensate or shower pump.
Mounting Brackets
The four mounting brackets provided should be placed around edge of drain pan as equally spaced
as possible. Secure a/c unit to a at level mounting surface. Brackets are provided. Customer is to
supply the necessary hardware such as screw/bolts, and washers. See Figure 4.
Follow each one of the steps as explained on this manual, any deviation from the procedure
explained herein constitutes improper installation of the unit and therefore waives and forever
discharges CTM Marine and its subsidiaries from any liability in connection to the installation;
use; and functioning of the unit and any and all systems and parts connected to it.

CTM Marine Self-Contained CT Installation & User Manual
13
Ducting
Good airow is critical for the performance of the entire system. It is highly
dependent on the quality of the ducting installation. The ducting should be run
as straight, smooth and taut as possible minimizing the number of 90° bends (two 90°
bends can reduce airow by 25%).
All ducting should:
>Be appropriately sized for each application.
>Run as smoothly and taut as possible.
>Have as few bends or loops as possible.
>Be securely fastened to prevent sagging during boat operation.
>Have all excess ducting lengths trimmed off.
>Not be attened or kinked.
>Insulated when located in high heat load areas (hull side,
mechanical compartments, etc.).
>Be properly protected against potential damage when
routed through open areas.
1. Slide back the berglass insulation duct to reveal the inner mylar duct
hose.
2. Put the mylar duct hose around the mount ring.
3. To make sure the mylar duct hose doesn't slide out, screw 3-4 stainless
steel screws through the duct hose into the mount ring. Make sure a few
wires from the mylar duct are captured by the screws.
4. Slide back the berglass insulation duct and cover the inner mylar duct
hose, and mount ring. Secure with high-quality aluminum foil tape or any
condensation inhibiting tape. See gure 6.
Fiberglass Insulation Duct
Inner Mylar Duct Hose
Mount Ring
Screws
Scre w
s
Aluminum Foil Tape
1
2 3
4
Figure 6
>If you install a transition box,
make sure that the total area of
supply air ducts going out of the
transition box is at least equal to the
area of the supply duct going into the
box.
>The supply air grille should be installed
as high as possible in such a manner that
provides a uniform air distribution
throughout the cabin.
>The return air grille should be located
as low as possible and as close to the a/c
unit as possible.
CARBONMONOXIDE HAZARD
>Do not route ducting through
engine room or any area where
it may be exposed to dangerous vapors
or exhaust fumes.
!
>Refer to the Minimum Duct Air
Grille Sizes per BTU Capacity
table on page 6, for duct and grille size
references.

CTM Marine Self-Contained CT Installation & User Manual
14
Seawater System
Refer to the drawings below for an overview of how the seawater system
should look like:
Consider the following instructions when setting up the seawater system
of your air conditioning unit. Failure to follow this procedure will void the
warranty:
1. Place a clam-shell type thru-hull tting as far away from the water line
as possible. Slots should be directed towards the bow to obtain positive
pressure in the suction line.
2. Place a bronze seacock on the thru-hull tting.
3. Place a seawater strainer below the level of the pump.
4. Connect the seacock and the strainer with a reinforced marine-grade
hose.
5. The pump should be install at least 30 inches below the waterline,
except when a self-priming pump is used.
6. Connect the strainer and the pump with a reinforced, marine-
grade hose.
7. Connect the pump's outow to the coil inow (See page 5to locate
the coil inow) with a 5/8 inch reinforced, marine-grade hose.
8. Connect the a/c unit discharge from the coil outow (See page 5 to
locate the coil outow) with a 5/8 inch reinforced, marine-grade hose.
>The a/c seawater system should
have a dedicated thru-hull tting
for the pump.
>The inlet for the thru-hull, seacock, hose, and
strainer should not be smaller than the pump
inlet.
>The pump strainer assembly should be
installed with a gentle upwards slope from the
seacock to the pump.
>Keep all the piping as short as possible
without kinks or loops where air can become
trapped.
>Avoid 90º elbow ttings as much as possible.
>Ensure that the pump head is rotated toward
the direction of water ow.
>Use seal tape on all threaded connections.
>Double-clamp all hose connections with
stainless steel clamps.
>Connect all metallic parts in contact with
seawater to the vessel's bonding system.
Steady upward ow from inlet
to unit then downward to
outlet.
Pump may be placed
above waterline if it's
self-primed.
>It is strongly recommended to
install an air-bleeder system both in
the suction line as well as immediately after the
discharge outlet of the pump.
1
34
5
67
8
WATER LINE
2
1
3
4
5
67
8
2
WATER LINE
WATER LINE
WATER LINE
1. Thru-hull tting 2. Seacock
3. Strainer 4. Seawater Pump
5. Coil inow 6. A/C Unit
7. Coil outow 8. Seawater Outlet
CORRECT
Water
Flow
Pump and strainer must be below
waterline. Pump head must be rotated
towards the water ow.
INCORRECT
Hoses must not have kinks or
loops where air can become
trapped.
INCORRECT
Strainer must bebelow
waterline.
INCORRECT
Pump may be placed
above waterline if it's
self-primed.
Water
Flow
1
3
4
5
67
8
2
1
34
5
67
8
2

CTM Marine Self-Contained CT Installation & User Manual
15
FIGURE 12 BOARD #40001C
BOARD #40003C
Auxiliary
Heat Spade
Terminal
Ground
8-Pin
Display Jack
High/Low
Pressure
Switches
6-Pin
Display Jack
Temperature
Sensor Jack
Water in/out
& Outside Temperature
Sensor Terminals
L2 (-)
L1 (+)
L2 Fan (-) L1 Fan (+)
L1 Valve (+)
L1 Pump (+)
L2 Pump (-)
L2 Comp. (-)
L1 Comp. (+)
>Make sure all metallic parts in
contact with saltwater are properly
grounded and bonded properly to the vessel's
bonding system. Failure to follow these
instructions will void the warranty.
>Each a/c unit installed requires a dedicated
circuit breaker. For installations of two or more
units sharing the same pump, the pump wires
will be connected to a pump relay panel (PRP),
which in turn has its own dedicated circuit
breaker sized for the pump (20 A max).
>Electrical connections in the bilge and/or
below the waterline should be sealed with heat
shrink type butt splices.
>Field wiring must comply with ABYC
electrical codes. Power to the unit must be
within the operating voltage range indicated
on he data plate. Properly sized fuses or HACR
circuit breakers must be installed for branch
circuit protection. Refer to the data plate for
max fuse/circuit breaker size (mfs) and
minimum circuit capacity (mca).
>ABYC standards are available
from :
American Boat and Yacht Council
613 Third Street, Suite 10
Annapolis, MD 21403
Phone: [phone]
Fax: [phone]
FIGURE 13
Auxiliary
Heat Spade Terminal
Ground
8-Pin
Display Jack
High/Low
Pressure
Switches
6-Pin
Display Jack
Temperature
Sensor Jack
Soft Start
Board
Water in/out
& Outside Temperature
Sensor Terminals
L2 (-)
L1 (+)
L2 Fan (-) L1 Fan (+)
L1 Valve (+)
L1 Pump (+)
L2 Pump (-)
L2 Comp. (-)
L1 Comp. (+)
Electrical Connections
The following must be observed when making the electrical connections:
1. In accordance with ABYC standard E-8, or equivalent, the Alternating
Current (AC) ground (green wire) must be connected to the ground
terminal (marked "GRND") on the AC input terminal block of the unit(s)
for supply.
2.Connections between the vessel's AC system grounding
conductor (green wire) and the vessel's Direct Current (DC)
negative or bonding system should be made as part of the
vessel's wiring, per ABYC standard E-9, or equivalent.
3. When servicing o replacing existing equipment that
contains a chasis mounted ground stud, the service person
or installer must check the vessel's wiring for the existence of the
connection required in item 2 above.
Figure 12 shows the Standard U-Board. Figure 13 shows the Soft-Start U-
Board.

CTM Marine Self-Contained CT Installation & User Manual
16
Follow each one of the steps as explained on this manual, any deviation from the procedure
explained herein constitutes improper installation of the unit and therefore waives and forever
discharges CTM Marine and its subsidiaries from any liability in connection to the installation;
use; and functioning of the unit and any and all systems and parts connected to it.

CTM Marine Self-Contained CT Installation & User Manual
17
Follow each one of the steps as explained on this manual, any deviation from the procedure
explained herein constitutes improper installation of the unit and therefore waives and forever
discharges CTM Marine and its subsidiaries from any liability in connection to the installation;
use; and functioning of the unit and any and all systems and parts connected to it.

CTM Marine Self-Contained CT Installation & User Manual
18
Display Control
CTM Marine Split System units are compatible with most thermostats currently in the market. Below
are the most common thermostats displays used by major marine air conditioner manufacturers.
DISPLAY MODEL 6-PIN CABLE 8-PIN CABLE
Smart Touch / Easy
Touch (wi-)
SMXIR
Passport I/O
Elite II
SMXII
Needs Adapter
#290340229
Needs Adapter
#763100043

CTM Marine Self-Contained CT Installation & User Manual
19
Troubleshooting
Always refer to the user manual of your digital control for troubleshooting as well.
PROBLEM POSSIBLE CAUSE POSSIBLE SOLUTION
System won’t start
EV handler circuit breaker is
OFF. Turn circuit breaker ON at the main vessel’s panel.
Wrong wiring terminal strip Check the wiring diagram and make the
necessary corrections
Input-line Voltage is
insufcient.
Check power source, either shore or generator
power for proper voltage. Check wiring terminals
for proper sizes and connections. Verify with a
volt-meter that power at the unit matches the
power source’s voltage.
Fan is not running Refer to the troubleshooting section of your digital control manual
Unit is not cooling
Temperature set point. Lower temperature to desired temperature on
display control.
Obstructed seawater ow
Clean seawater strainer, check for any
obstructions at scoop thru-hull inlet, and check
for good steady ow from overboard discharge.
Seawater pump may be air- Remove hose from pump discharge to purge air
locked from line.
Loss of refrigerant gas Check unit for leakage and call an certied
technician.
Seawater temperature to
high for cooling.
Seawater temperature will directly affect the
efciency of your unit. Your unit will effectively
cool your boat with seawater temperatures up to
90ºF (32.2ºC).
Fan coil is iced Refer tot he troubleshooting section of your
digital control manual
Fan is not running Refer tot he troubleshooting section of your
digital control manual
Seawater Plumbing is air-
locked
Make sure the seawater plumbing system is
properly installed per the instructions in this
manual.
High-Pressure Switch is
open due to improper
seawater ow
Strainer or intake may be plugged, seacock may
be closed. Check seawater hose for kinks or
collapses. Verify pump operation.

CTM Marine Self-Contained CT Installation & User Manual
20
PROBLEM POSSIBLE CAUSE POSSIBLE SOLUTION
Unit is not heating
Temperature set point. Lower temperature to desired temperature on
display control.
Wrong wiring terminal strip Check the wiring diagram and make the
necessary corrections
Obstructed seawater ow
Clean seawater strainer, check for any
obstructions at scoop thru-hull inlet, and check
for good steady ow from overboard discharge.
Seawater pump may be air- Remove hose from pump discharge to purge air
locked from line.
Loss of refrigerant gas Check unit for leakage and call an certied
technician.
Seawater temperature to
low for heating.
Seawater temperature will directly affect the
efciency of your unit. Your unit will effectively
heat your boat with seawater temperatures as
low as 40ºF (4.4ºC).
High-Pressure Switch is
open due to improper
seawater ow
Strainer or intake may be plugged, seacock may
be closed. Check seawater hose for kinks or
collapses. Verify pump operation.
High-Pressure Switch is
open due to high seawater
temperature
The unit may cycle on high pressure if seawater
temperature is above 55ºF (12.8ºC), increase fan
speed.
Unit is in “cool only” mode,
or reversing valve may be
stuck.
Tap reversing valve lightly with a rubber mallet
while is in heat mode. Call a certied technician if
this doesn’t work.
Low Airow
Airow is blocked Remove obstructions from the return air stream. Clean return-air lter and grille. Check crushed or
obstructed ducting.
Fan speed set to manual
low Set fan speed to desired speed.
Fan coil is iced
Thermostat set too low. Raise temperature
Improper ow Remove obstructions from the return air stream. Clean return-air lter and grille. Check crushed or
obstructed ducting.