Truma Combi D comfort plus

• Serial number
• Operating manual/type label
• Fuel line color (this is found underneath the vehicle). A Combi G will have a black fuel line and Combi D will have a clear/cloudy fuel line. A propane-powered Combi will not have a fuel line connected to the vehicle fuel tank.

The Combi D furnace requires ultra-low-sulfur diesel (ULSD) fuel with max. 15 ppm sulfur according to ASTM D975 and SOR/2005-305.

• Even small amounts of other volatile fuels or solvents mixed with diesel can increase the risk of fire or explosion.
• Operation with biodiesel is not allowed.

We recommend keeping the gas tank at least 1/4 tank full to support uninterrupted fuel delivery.

If your Truma Combi D will not operate on 120 V power, please try these troubleshooting steps:

1. Is there 120V power available to the vehicle?
2. Is the 12V master switch on?
3. Check the icon on the CP plus to make sure it shows a plug on the bottom right.
   • If not, then the unit does not have power.
   • If yes, you will likely see an error code as this indicates the heating elements or board may be damaged. Please contact Truma Customer Care for additional support.
4. Does the Combi operate in fuel-mode only?
5. Is the temperature limiter reset tripped? This is indicated by the following warning and error codes: W45, E112 H, E212 H.
   • If so, run cold water through the Combi for a few minutes. Once the furnace has cooled, it will switch on again automatically.
6. Check 12V power to the Combi
   • Turn off power to the Combi
   • Remove the PCB cover where the 12V data cables connect and check the connection to the 12V fuse
   • Replace the PCB cover
   • Check the external breaker box and verify 120V connection
   • Reconnect power and try again

If you verify all the steps above and are still having problems, contact Truma Customer Care for additional support.

Troubleshooting:

• Don’t clear and restart too many times, or you may lock out your Combi.
• Check that the gas tank is at least ¼ full to ensure uninterrupted fuel delivery.
• If you are at a high elevation, start the Combi at a lower elevation so it is warm before starting it for the first time at elevation.

Error Codes on the CP plus:

• If no flame is detected after the first three repeat starts, E560 will appear. You will be required to acknowledge and clear the code on the CP plus each time this appears.
• If the restart is not successful the fourth time, E561 will appear indicating the furnace cannot restart. You will be required to acknowledge and clear the code on the CP plus when this happens. Please note that clearing this code after the fourth restart may result in the device locking up, making it inoperable.
• The device is locked after the fifth restart. Error message 565 will appear when locked.
• After a total of 5 unsuccessful starting attempts (initial and repeat starts) with no flame, the system is locked.
• At this time, the unit can only be unlocked by the Truma Service Center or one of our authorized Service Partners. Please contact us for assistance

If the system has been sitting for an extended period of time: 

• Air bubbles may have formed in the fuel lines due to the chemical properties of gasoline, so multiple start attempts may be necessary. This does not indicate a defect in the device. To fill the fuel lines, you might have to start the furnace several times.

If you are above 12,000 feet and are trying to cold start the Combi D:

• Drive to a lower elevation (below 10,000 feet) and start the Combi D, giving it time to warm up before driving back up to a higher elevation. The potential for cold starts and restarts decreases if the unit is already warm.

If the system has recently been running:

• If the fuel level is above 1/4 tank and the Combi has not been cold-started, reduce the heat output to put less stress on the system.

If the problem continues, please contact us for assistance.

If your Truma Combi will not stay lit, but you are not receiving an error code, check the following items:

• Make sure the water in the tank has not frozen. If the tank freezes and becomes swollen (which can be determined by looking at the Combi housing to see if it is misshapen) it can restrict the airflow into the ducting. This could cause the unit to overheat and cycle off.
• Check the location of the temperature sensor. If the sensor is in an area that does not get good airflow, in front of vents, or next to open windows and/ or doors, it may not be measuring properly. This could impact the performance of the unit.

If the issue persists, please contact Truma Customer Care for additional support.

If a generator is installed, start the generator before starting the Combi D. This will ensure the Combi D does not draw air from the generator fuel line.

It is recommended to reduce the risk of condensate dripping down the exterior wall of the RV, which can cause damage to the side wall over time. The spout can also be used for the Combi propane variants, but because propane tends to have lower particulate matter emissions it is not required.

Yes, it can remain attached while driving. Since it just clips into place, it can be removed then reattached once parked and prior to using the Combi.

We recommend it be replaced to help protect the sidewall of the RV. Replacements will be available on our Amazon store.

Please refer to your RV manufacturer’s instructions for winterizing and bypass valves.

1. Place a vessel that’s at least 2.64 gallons (10 liters) underneath the drainage outlet of the drain valve.
2. Use the main switch or pump switch to turn off the power to the water-pump
3. Turn off or disconnect the city water connection if present
4. Open all water release points, e.g. cold and hot water faucets, showers, toilets
5. Flip yellow handle to be in line with valve body to drain.