Duo-Therm DIAGNOSTIC SERVICE MANUAL …

1 1 DIAGNOSTIC SERVICE MANUALDuo-Therm comfort Control Center SystemsSYMPTOM CAUSE REFER TO STEPThis program will address the most common system problems associated with the Duo-Therm comfort ControlCenter supplied by The Dometic Corporation. Our intent is to provide you with a guideline of checks to make,should you encounter one of the following CONTROL CENTER SECTION:1. Turn to "ON" No Turn to "ON" Has display, improper Multiple Units: One unit operates and improperoperation on other unit(s).ROOF MOUNTED AIR CONDITIONER SECTION:1. Unit does not run: No fan, no Fan operates: Compressor will not come on (doesnot "hum")3. Fan Operates: Compressor tries to start, cycles"OFF" and "Hums" again, or blows circuit 1 MDC Volts 4 Cable Assembly Power Module Board Control Center 1 Reset 1 MConfiguration 2 Wiring Power Module Board Control Center 1 Reset 1 MConfiguration 2 Wiring Power Module Board Control Center 2 Operation 1AC

2 Voltage Voltage 4 Breaker Assembly Control Center Power Module Board 1 Cable Assembly Control Power Module Board AComfort Control Center Voltage or Run Capacitor & ControlOverload Protector ,A2,A3B1,B2,B3,B7,B8,C,DDiagnostic SERVICE Manuals2 Duo-Therm comfort Control Center SystemsDIAGNOSTIC SERVICE MANUALSYMPTOMCAUSEREFER TO STEP(Roof Mounted Air Conditioner Sec.)

3 Continued) operates: compressor runs for a short while,cycles "OFF", cycles back "ON". runs, no runs, but not on all distribution box unit: Evaporator in ceiling unit: Evaporator distribution box unit: Insufficient cooling,compressor runs Duct in ceiling unit: Insufficient cooling, compressorruns Flow Distribution Power Module Control Power Module Control Flow Tube Flow Distribution Tube Flow Gain/Heat Flow Distribution Gain/Heat SERVICE MANUALDuo-Therm comfort Control Center SystemsSYMPTOMCAUSEREFER TO STEP(Roof Mounted Air Conditioner Sec. continued)11. Air distribution box unit: Insufficient cooling withreduced air Duct in ceiling unit: Insufficient cooling with reducedair Excessive Noisy MOUNTED HEAT PUMP does not run: No fan, no operates: Compressor will not come on (doesnot "hum". operates: Compressor tries to start, cycles"OFF" and "hums" again, or blows circuit operates; compressor runs for a short time,cycles "OFF", cycles back "ON".

4 Air Flow flow Distribution Power Module Control Blades Control Power Module Power Module Control or Run & Flow Distribution ,B3,B4,B8C,D4 Duo-Therm comfort Control Center SystemsDIAGNOSTIC SERVICE MANUALSYMPTOMCAUSEREFER TO STEP(Roof Mounted Heat Pump Sec. continued) runs, no runs, but not on all distribution box unit: Inside coil in ceiling unit: Inside coil Distribution Box Unit: Insufficient cooling orheating, compressor runs Duct in ceiling unit: Insufficient cooling or heating,compressor runs Air distribution box unit: Insufficient cooling orheating with reduced air Duct in ceiling unit: Insufficient cooling or heatingwith reduced air Excessive cooling or Power Module Control Power Module Control Flow Tube Flow Distribution Tube Flow Gain/Heat Flow Distribution Gain/Heat Flow Flow Distribution Power Control SERVICE MANUALDuo-Therm comfort Control Center SystemsSYMPTOMCAUSEREFER TO STEP(Roof Mounted Heat Pump Sec.)

5 Continued)14. Unit operation in wrong mode (cool instead of heatpump or reversed)15. Noisy OperationBASEMENT (SINGLE COMPRESSOR)AIR CONDITIONER SECTION:1. Unit does not run; no fan, no Fan operates; compressor will not come on (does not"hum")3. Fan operates; compressor tries to start, cycles "OFF"and "hum" again, or blows circuit Fan operates; compressor runs for a short time, cycles"OFF", cycles back "ON".Operation1 Ambient Control Blades Control Power Module Power Module Control or Run & Flow Distribution ,B5,C,D6 Duo-Therm comfort Control Center SystemsDIAGNOSTIC SERVICE MANUALSYMPTOMCAUSEREFER TO STEP(Basement [Single Compressor] A/C )5. Compressor runs, no Fan runs, but not on all Evaporator Insufficient cooling, compressor runs Insufficient cooling with reduced air Excessive Noisy (SINGLE COMPRESSOR)HEAT PUMP SECTION:1.

6 Unit does not run; no fan, no Power Module Control Power Module Control Flow Tube Flow Distribution Gain/Heat Flow Distribution Power Module Control Blades A6,B6,C,DOperation1AC Control Power Module SERVICE MANUALDuo-Therm comfort Control Center SystemsSYMPTOMCAUSEREFER TO STEP(Basement [Single Compressor] H/P )2. Fan operates; compressor will not come on (does not"hum")3. Fan operates; compressor tries to start, cycles "OFF"and "hums" again, or blows circuit Fan operates; compressor runs for a short while,cycles "OFF", cycles back "ON".5. Compressor runs; no Fan runs; but not on all Inside coil Insufficient cooling or heating; compressor runs Power Module Control or Run & Flow Distribution Power Module Control Power Module Control Flow Distribution Tube Flow Distribution Gain/Heat comfort Control Center SystemsDIAGNOSTIC SERVICE MANUALSYMPTOMCAUSEREFER TO STEP(Basement [Single Compressor] H/P )9.

7 Insufficient cooling or heating with reduced air Excessive cooling or Unit operates in wrong mode (cool instead of heatpump or reversed)12. Noisy (DUAL COMPRESSOR)AIR CONDITIONER SECTION:1. Unit does not run; no fan, no Fan operates; compressor will not come "ON" (doesnot "hum")3. Fan operates; compressor tries to start, cycles "OFF"and "hums" again, or blows circuit Flow Distribution Power Module Control Control Blades Control Power Module Power Module Control or Run & SERVICE MANUALDuo-Therm comfort Control Center SystemsSYMPTOMCAUSEREFER TO STEP(Basement [Dual Compressor] A/C )4. Fan operates; compressor runs for a short while,cycles "OFF", cycles back "ON".5. Compressor runs, no Fan runs, but not on all Evaporator Insufficient cooling; compressor runs Insufficient cooling with reduced air Excessive Noisy Flow Distribution Power Module Control Power Module Control Flow Distribution Flow Distribution Gain/Heat Flow Distribution Power Module Control Blades comfort Control Center SystemsDIAGNOSTIC SERVICE MANUALSYMPTOMCAUSEREFER TO STEPBASEMENT (DUAL COMPRESSOR) HEAT PUMPSECTION:1.

8 Unit does not run; no fan, no Fan operates; compressor will not come on (does not"hum")3. Fan operation; compressor tries to start, cycles "OFF"and "hums" again, or blows circuit Fan operates; compressor runs for a short while,cycles "OFF", cycles back "ON".5. Compressor runs; no Fan runs; but not on all Inside coil Control Power Module Power Module Control or Run & Flow Distribution Power Module Control Power Module Control Flow Distribution Tube SERVICE MANUALDuo-Therm comfort Control Center SystemsSYMPTOMCAUSEREFER TO STEP(Basement [Dual Compressor] H/P )8. Insufficient cooling or heating; compressor runs Insufficient cooling or heating with reduced air Excessive cooling or Unit operates in wrong mode (cool instead of heatpump or reversed)12. Noisy Flow Distribution Gain/Heat Flow Distribution Power Control Control Blades SERVICE MANUALDuo-Therm comfort Control Center SystemsSECTION CRYSTAL DISPLAY The comfort ControlCenter is equipped with a liquid crystal display (LCD)that identifies the mode of operation, the temperatureset-point, the zone identification and the fan comfort Control Center is designed to accept andcontrol many varied air conditioning and gas heatingappliances.

9 When you begin to first operate theComfort Control Center, you will see that the LCDreadout will only show the options available based onthe appliances installed on your vehicle. An incandes-cent light will illuminate the LCD area when a selectorbutton is pushed for easy reading at all SPEEDS Possible available fan speeds are:LOW, MEDIUM, HIGH and AUTO. To select thedesired fan speed, momentarily depress the FANpush button. You will need to continue to depress andrelease the FAN button until the desired fan speed isshown in the LCD readout area of the comfort recreational vehicle manufacturer has equipped thevehicle with Duo-Therm 's comfort Control Center . TheComfort Control Center has been designed for you toeasily operate all the air conditioning and gas heatingappliances found in your vehicle from one order to familiarize yourself with the operation of theComfort Control Center, the following diagram along withthe accompanying text will explain all the functional char-acteristics of the SELECTOR BUTTON Modes of operationavailable are: OFF, FAN ONLY, COOL, HEAT PUMP,FURNACE and HEAT STRIP.

10 Remember, the LCDreadout will only show the options available based onthe appliances installed on your vehicle. To select themode of operation, momentarily depress the MODE push-button. You will need to continue to depress andrelease the button until the desired mode is shown inthe LCD readout area on the comfort Control determine the comfort Control Center optionsavailable to you, depress and release the MODE push-button until it goes through all SELECTOR BUTTONS The tem-perature Set-point range is from 40 to 99 of Fahrenheit or Celsius standard isdone at the time of your manufacturer's installation ofthe Climate Control Center. To set the temperature atyour comfort level, simply depress and release the UPor DN push-button until the desired temperature isshown in the LCD readout area of the comfort AND STAGE SELECTOR BUTTONS AZONE is also established at the time of installation ofthe comfort Control Center.