Duo-Therm 39125 User Manual

AIR CONDITIONER & HEAAIR CONDITIONER & HEA
AIR CONDITIONER & HEAAIR CONDITIONER & HEA
AIR CONDITIONER & HEA
T PUMPT PUMP
T PUMPT PUMP
T PUMP
SERVICE MANUSERVICE MANU
SERVICE MANUSERVICE MANU
SERVICE MANU
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This Service Manual is the result of the dedication of The Dometic Cor-
poration and its engineers to providing service people the necessary
instructions for making accurate analysis of certain conditions. Provided
is a comprehensive guide designed to lead a qualified mechanic through
the Service Manual to locate and solve symptoms that may occur.
Dometic continues their commitment to providing the most up to date
information about servicing Duo-Therm Air Conditioners and Heat Pumps.
Form No. 3108892.013 10/00
©2000 The Dometic Corporation
LaGrange, IN 46761
Manual Compliments of
Northwest RV Supply
Printed From
http://www.nwrvsupply.com

Duo-Therm 39125 Specifications

General

Brand	Duo-Therm
Model	39125
Category	Air Conditioner
Language	English

Summary

Section C - Components

C1-C5: Motor and Compressor Components

C17. Printed Circuit Boards

C18. Thermostat Types

C20. Sealed System and Refrigerant

Section D - Configuration

D. Configuration

Section E - Symptom/Cause Chart

DUO-THERM ROOF MOUNTED HEAT PUMPS

7. Inside Coil Freezes up (Air Distribution Box)

Identifies causes of evaporator coil freezing in cool mode (air distribution box).

8. Inside Coil Freezes up (Duct in Ceiling)

Troubleshooting evaporator coil freezing in cool mode (duct in ceiling).

9. Insufficient cooling or heating; compressor runs constantly (Air Distribution Box)

Addresses causes of continuous compressor operation without cooling/heating.

10. Insufficient cooling or heating compressor runs constantly. (Ducts in ceiling)

Diagnosing continuous compressor operation in ducted systems.

11. Unit operates in wrong mode (cool Instead of heat or reversed)

Troubleshooting incorrect mode operation or reversed cycle.

12. Insufficient cooling or heating; compressor cycles off and on...(Air Distribution Box)

Diagnosing short cycling issues in air distribution box systems.

13. Insufficient cooling or heating; compressor cycles off and on...(Duct in Ceiling)

Troubleshooting short cycling in ducted ceiling systems.

14. Noisy operation. (Cooling or Heating Mode)

15. Water leaks into RV. (Cooling Mode)

16. Turn to furnace; no furnace operation

Diagnosing issues when the furnace fails to operate.

17. Turn to electric heat strip; no operation

Troubleshooting electric heat strip operation failures.

DUO-THERM BASEMENT AIR CONDITIONERS

1. Unit does not run; no fan, no compressor

Lists causes for basement unit failure to start.

2. Fan operates; compressor will not come on

Identifies causes when basement unit fan runs but compressor does not.

3. Fan Operates; compressor tries to start, cycles ìOFFî and hums again, or blows circuit breaker.

Troubleshooting basement unit starting issues.

4. Fan operates; compressor runs for a short while, cycles off, cycles back on hums, blows circuit breaker or does not run.

Addresses basement unit short cycling and intermittent operation.

5. Compressor runs, no fan

Troubleshooting when basement unit compressor runs but fan does not.

6. Compressor runs, fan runs, but on one speed only.

Diagnosing single-speed fan operation in basement units.

7. Inside Coil Freezes up

Identifies causes of evaporator coil freezing in basement units.

8. Insufficient cooling or heating compressor runs constantly...

Addresses continuous compressor operation in basement units.

9. Unit operates in wrong mode (cool Instead of heat or reversed)

Troubleshooting incorrect mode operation in basement units.

10. Insufficient cooling or heating; compressor cycles off and on...

Diagnosing short cycling in basement units.

11. Excessive cooling or heating; compressor will not shut off.

Addresses continuous compressor operation in basement units.

12. Noisy operation.

13. Turn to furnace; no furnace operation