+2 more
Ontour T, Prestige THobby Heating
(Motorhomes, 2026 Model Year)
View official manual on manufacturer's site ↗Master Troubleshooting & Diagnostics Matrix
| Error Code / Indicator | Symptom / Meaning | Possible Cause | Step-by-Step DIY Fix | Suggested Actions |
|---|---|---|---|---|
N/A | Electric operation: 230V power supply interrupted while 12V supply is switched on (heating system) | 230V power supply interruption | The display shows an error code. Once the 230V supply comes back, the heating restarts on its own using the settings it had before, and the error code clears. | DIY Safe |
N/A | Mixed-mode Combi Gas heating develops a combustion fault (e.g. running low on fuel) | Malfunction in the combustion process such as lack of fuel | The system automatically falls back to electric heating. If you're running in mixed mode, you'll need to sort out what's causing the fault first, then use the control panel to turn the heating off and on again to clear it. | DIY Safe |
W 42 H | Truma CP plus control panel warning message | One of the heating system's operating parameters has drifted outside its normal range | Select the warning icon using the adjusting knob/pushbutton, then press it again to read out the warning code shown (format: W for Warning, a code number, then H for Heating). Once whatever caused it has been sorted, press the knob/pushbutton once more to return to the normal setting mode. If it hasn't been sorted, use the reset button instead - the panel will stay in its warning state and keep the icon showing, though every other connected device carries on working as normal. | DIY Safe |
E 112 H | Truma CP plus control panel malfunction | — | The control panel immediately goes to Malfunction mode and displays the error code. Press the adjusting knob/pushbutton if the cause is eliminated so the corresponding device restarts. Press the 'reset' button if the cause is not eliminated. | DIY Safe |
N/A | FrostControl safety/drain valve temperature is lower than approx. 3°C | Sub-zero or low ambient temperature below approx. 3°C | The valve's push button pops out on its own, and the boiler drains automatically through the drain outlet - no action needed. | DIY Safe |
N/A | Truma Combi Gas/Diesel heating develops a fault partway through the combustion process (e.g. running low on fuel) | A fault has occurred in the gas or diesel combustion process. | The system automatically falls back to electric heating. If you're running in mixed mode, you'll need to sort out what's causing the fault first, then use the control panel to turn the heating off and on again to clear it. | DIY Safe |
N/A | An error code appears on the heating display after a 230V mains interruption while running on electric power (with the 12V supply still on) | The 230V mains supply has been interrupted while the heating is running on electric power. | This clears itself - once the 230V supply comes back, the heating restarts automatically with its previous settings and the error code goes away on its own. | DIY Safe |
Frequently Asked Questions
Q: How do I manually open the FrostControl valve to drain the water system?
Rotate the switch a full 180° round until it locks - the pushbutton pops out and the water drains from the container via the drain pipe.
Q: How do I manually close the FrostControl valve?
Confirm the rotary switch sits in the 'Operation' position (in line with the water supply) and has clicked into place, then push the button in until it locks into the 'Closed' position - the valve needs to be above roughly 7°C for this to work.
Q: How do I read a warning or malfunction code on my heating control panel?
A warning icon means one of the heating system's operating parameters has drifted outside its normal, defined range - the device keeps running regardless, and the icon clears itself once that parameter settles back within range. Press the control knob/pushbutton to display the current code (shown as a letter + number, e.g. 'W 42 H' = Warning, code 42, Heating) - check this against the error list in your Truma documentation to find the cause.
Once the cause is resolved, press the control knob/pushbutton again to clear it. A malfunction code (shown as 'E' instead of 'W') means the control panel has gone into Malfunction mode and the device has stopped - once the cause is resolved, pressing the control knob/pushbutton restarts the device. If the cause hasn't been resolved, use the 'reset' button - if it still isn't cleared, the malfunction will reappear once the control panel finishes its internal lag/restart period (this can take a few minutes).
Other connected devices can still be operated while one device is showing a warning or malfunction.
Q: What do the LED colours mean on my Truma CP Classic heating control panel?
Green means the device is running normally. Yellow means the boiler is currently heating up (illuminated) or there is a warning (blinking). Red means a malfunction has occurred. For detailed error diagnosis beyond these colours, refer to the manufacturer's own operating instructions for your specific control panel.