Dometic Waeco CoolMatic MDC
Official technical documentation and workshop diagnostics for Dometic Waeco CoolMatic MDC.
Technical Specifications
Master Troubleshooting & Diagnostics Matrix
| Error Code / Indicator | Symptom / Meaning | Step-by-Step DIY Fix | Suggested Actions |
|---|---|---|---|
N/A | Compressor does not run (1 flash on error LED) Possible Cause: Battery protection shutdown; battery voltage outside set range (UKL <= UIN) | Charge battery, check cable connections, check for loose cables, corrosion, or incorrect cable cross-section. | DIY Safe |
N/A | Compressor does not run (2 flashes on error LED) Possible Cause: Fan overcurrent shutdown; fan draws more than 0.5 A average or 1 A peak from electronic unit | Replace defective fan. | DIY Safe |
N/A | Compressor does not run (3 flashes on error LED) Possible Cause: Motor start error; rotor stuck or differential pressure in cooling system too high (> 5 bar) | Check compressor and cooling system for blockage. | DIY Safe |
N/A | Compressor does not run (4 flashes on error LED) Possible Cause: RPM too low; overloaded cooling system cannot maintain minimum motor speed of 1900 RPM | Improve ventilation, clean condenser, or reduce load. | DIY Safe |
N/A | Compressor does not run (5 flashes on error LED) Possible Cause: Thermal shutdown of electronic unit due to high load or ambient temperature | Improve ventilation around unit and ensure ambient temperature is within limits. | DIY Safe |
N/A | UKL = 0 V (No voltage at electronics terminals) Possible Cause: Interruption in battery-to-electronics cable, defective main switch, or blown supply line fuse | Establish connection, replace main switch, or replace line fuse. | DIY Safe |
N/A | Compressor runs constantly Possible Cause: Thermostat sensor has no contact with the evaporator, or thermostat is defective | Secure thermostat sensor or replace thermostat. | DIY Check / Tech Fallback |
N/A | Cooling capacity drops, interior temperature rises Possible Cause: Evaporator iced over, high ambient temperature, poor ventilation, or dirty condenser | Defrost evaporator, clean condenser, improve ventilation, or replace defective fan. | DIY Safe |
N/A | Loud humming noise Possible Cause: Refrigerant circuit component touching cabinet wall or foreign body jammed between device and wall | Carefully bend the component away from the wall or remove the foreign body. | DIY Safe |
Frequently Asked Questions
Q: What does climate class of SN (Sub Normal) mean?
The climate class SN (Sub Normal) defines the intended ambient temperature range for the absorption fridge's optimal operation.
Q: What’s the cooling performance in warmer ambient temperatures?
Cooling performance for absorption fridges is affected by warmer ambient temperatures. Ensure proper ventilation around the unit as detailed in the manual to maintain performance.
Q: How to operate an RMxxxx with a solar panel?
To operate an RMxxxx series absorption fridge with a solar panel, ensure the solar system provides adequate 12V DC power or sufficient battery storage to handle the power requirements, particularly when running on DC mode.
Q: My RMxxxx needs to be replaced. What would be an alternative?
When replacing an RMxxxx series refrigerator, look for current Dometic absorption or compressor models matching the physical dimensions and energy source requirements of your motorhome cutout.
Q: The refrigerator does not work In AC power mode?
Check if the vehicle is properly connected to the AC mains supply, verify that the AC fuse in the motorhome is intact, and ensure the refrigerator is switched on to AC mode on the control panel.
Q: The refrigerator does not work In DC power mode?
DC mode (12V) typically only works while the vehicle engine is running and the alternator is supplying power, preventing the vehicle starter battery from draining. Check the 12V DC fuses, vehicle ignition connection, and input voltage at the refrigerator terminals.
Q: The refrigerator does not work In GAS mode?
Ensure the gas cylinder valve is open, the main gas shut-off valves in the motorhome are open, and there is no air trapped in the gas line (try igniting another gas appliance first). Check if the igniter is sparking and that the burner is clean.
Q: In automatic mode: The refrigerator is being operated with gas although it is connected to The AC power supply?
In automatic energy selection mode, if the AC voltage is outside the acceptable tolerance range or unstable, the control system automatically switches to gas mode as a safety fallback. Check the AC supply voltage and connections.
Q: The refrigerator is not cooling adequately?
Verify that ventilation grilles are not blocked, check that the thermostat is set correctly, ensure the door seals tightly, do not overpack the interior restricting airflow, and verify that the selected energy source (AC, DC, or Gas) is actively functioning.
Q: WARNING type fault messages
WARNING type fault messages indicate a non-critical operational issue or prompt. Consult the user manual for the specific warning code displayed on the 10-series control panel to take corrective action.
Q: ERROR type fault messages
ERROR type fault messages indicate a critical system failure that stops the refrigerator from functioning safely on the current energy source. Check the specific error code on the display, troubleshoot the underlying power, gas, or ventilation issue, or contact customer service.