Operating instructions

11
This program will address the most common system problems associated with the
Duo-Therm Heat PumpsDuo-Therm Heat Pumps
Duo-Therm Heat PumpsDuo-Therm Heat Pumps
Duo-Therm Heat Pumps sup-
plied by The Dometic Corporation. Our intent is to provide you with a guideline of checks to make, should you
encounter one of the following symptoms.
1. MECHANICAL CONTROL
Unit does not run; no fan, no compressor.
2. ELECTRONIC & BIMETAL CONTROL
Unit does not run; no fan, no compressor.
3. MECHANICAL CONTROL
Fan operates; compressor will not come on (does
not hum).
4. ELECTRONIC & BIMETAL CONTROL
Fan operates; compressor will not come on (does
not hum).
5. MECHANICAL, ELECTRONIC & BIMETAL RELAY
CONTROL
Fan operates; compressor tries to start, cycles OFF
and hums again, or blows circuit breaker.
6. MECHANICAL, ELECTRONIC & BIMETAL RELAY
CONTROL
Fan operates; compressor runs for a short while,
cycles off, cycles back on, but doesn't run.
7. MECHANICAL CONTROL
Compressor runs, no fan.
8. ELECTRONIC & BIMETAL CONTROL
Compressor runs, no fan.
DUO-THERM ROOF-MOUNTED HEAT PUMPS
Operating Instructions 4E 60
AC voltage 1B 26
Breaker 3B 26
Selector switch 8E 63
Wiring 5B 27
Operating Instructions 5E/6E 60-62
AC voltage 1B 26
DC Voltage 7E 63
Breaker 3B 26
Wiring 11B 64
Thermostat 9E/B - 9E/C 64
Relay board 12E 71
Cable Assembly 10E 70
Wiring 5B 27
Selector Switch 8E 63
Thermostat 9E/A 64
Changeover thermostat 11E 71
Compressor 5C 36
Wiring 11B 30
Changeover thermostat 11E 71
Cable assembly 10E 70
Thermostat 9E/1B-9E/C 64
Relay Board 12E 71
Compressor 5C 36
AC voltage 1B 26
PTCR or start relay 4C 36
Start or run capacitor 2C/3C 35
Compressor 5C 36
Short cycle 9C 38
Air Flow obstruction 10C 38
Condenser fan 12C/E 44
Compressor 5C 36
Refrigerant system 13C 45
Wiring 5B 27
Selector Switch 8E 63
Run Capacitor 2C 35
Motor 1C 34
Wiring 11B 30
Run Capacitor 2C 35
Motor 1C 34
Thermostat 9E/B-9E/C 64
Relay Board 12E 71
Cable Assembly 10E 70
Relay, Fan Speed 12E 71
SYMPTOM CAUSE REFER TO PAGE