Truma Combi (E)
The Truma Combi (E) is a fan-assisted liquefied gas warm-air heater with an integrated 10-litre hot water boiler and, in 'E' variants, additional heating elements for 230V electrical operation. It provides simultaneous or independent space heating and water warming for caravans and motorhomes.
Technical Specifications
Master Troubleshooting & Diagnostics Matrix
| Error Code / Indicator | Symptom / Meaning | Step-by-Step DIY Fix | Suggested Actions |
|---|---|---|---|
N/A | Water taking an extremely long time to heat up Possible Cause: Water container furred | Descale water system using commercial descaling products, vinegar essence, or citric acid as outlined in the maintenance instructions. | DIY Safe |
N/A | Water running off – boiler cannot be filled Possible Cause: Safety / drain valve open | Close the safety / drain valve by ensuring the rotary switch is set to operation and pressing the pushbutton until it engages. | DIY Safe |
N/A | Boiler cannot be drained, even though the safety / drain valve is open Possible Cause: Safety / drain valve drainage socket blocked | Check opening for soiling such as slush, ice, or leaves, and remove obstruction if necessary. | DIY Safe |
N/A | Water dripping / flowing from drainage socket of the safety / drain valve Possible Cause: Water pressure too high | Check pump pressure to ensure it does not exceed 2.8 bar. If connected to a central water supply, install a pressure reducer to prevent pressures higher than 2.8 bar. | DIY Safe |
N/A | After the heater has been switched off, the FrostControl opens Possible Cause: Temperature at the FrostControl dropped below approximately 3 °C, causing it to open automatically | Switch the heater on to warm the installation compartment. Without heater operation, the FrostControl cannot be closed again until the temperature reaches approximately 7 °C, or use an optional heating element for FrostControl. | DIY Safe |
N/A | The FrostControl can no longer be closed Possible Cause: Temperature at FrostControl is less than approximately 7 °C, or the rotary switch is not set to operation | Switch the heater on to warm the environment above 7 °C, or turn the rotary switch of the FrostControl to the operation position and press the pushbutton until it engages. If the issue remains unresolved, contact an authorised service agent. | DIY Check / Tech Fallback |
Frequently Asked Questions
Q: Can the Combi be operated without water in the tank?
Yes, interior heating is possible both with and without water content, depending on the operational setting.
Q: What should I do if I smell gas inside the vehicle?
Immediately avoid ignition sources (extinguish naked flames, do not operate electrical switches, phones, or radios, do not start the engine), open windows and doors, evacuate all persons from the vehicle, shut off gas cylinders or the external gas supply, and have the entire system inspected and repaired by an expert.
Q: How do I protect the water boiler from frost damage?
If the vehicle is not in use during freezing periods, you must completely drain the water container via the safety/drain valve (FrostControl or manual drain valve). The system does not feature an internal active frost protection mechanism that prevents freezing without draining.
Q: What should I do if I smell gas in the vehicle?
Avoid ignition sources (extinguish naked flames, do not operate electrical switches, phones, or radios, do not start the engine), open windows and doors, evacuate all persons from the vehicle, shut off gas cylinders from the outside, and have the entire gas system inspected and repaired by experts.
Q: Can the Truma Combi be operated while driving?
Yes, provided an appropriate safety shut-off device like the Truma MonoControl CS gas pressure regulator is installed in accordance with UN ECE Regulation 122 to prevent uncontrolled gas escape during an accident.
Q: How do I protect the boiler from frost damage?
The Combi has no built-in frost protection. If there is a risk of frost and the vehicle is not in use, you must switch off the water pump, open all hot water taps, and open the FrostControl safety/drain valve to completely drain the 10-litre water container.
Q: How do I reset the 230V overheating protection on Combi E models?
Allow the heater to cool down, remove the electrical connector cover, and press the reset button located on the switch.
Q: Can the Truma Combi heat the interior without water in the boiler?
Yes, interior heating is possible both with and without water in the boiler depending on your operational setup.
Q: What should I do if I smell gas?
Extinguish all naked flames, do not operate electrical switches or mobile phones, open windows and doors, evacuate the vehicle, close the gas cylinders, and have the system inspected by an expert.
Q: How do I reset the 230V overheating protection?
Allow the heater to cool down, remove the connection cover on the power electronics, and press the reset button.
Q: What do the different LED colors mean for the operating mode?
Green means operational, and yellow indicates the warm water heat-up phase.
Q: What electrical power levels are available in electrical mode?
You can select 900 W or 1800 W depending on the setting.