Question 1

None of the LEDs light up, even with the appliance switched on and getting its operating voltage

Accepted Answer

Possible cause: The automatic restart lock has kicked in, e.g. following a power cut. Clear the fault by switching off, leaving it 5 seconds, then switching back on.

Question 2

Nothing lights up when it's switched on

Accepted Answer

Possible cause: No operating voltage or appliance/vehicle fuse defective. Check the 12V battery voltage and charge if needed, check every electrical plug connection, and check/replace the appliance's or vehicle's fuse.

Question 3

The green LED lights up once switched on, but the heater doesn't run

Accepted Answer

Possible cause: The control panel's temperature setting is below the current room temperature.. Turn the temperature setting up at the control panel.

Question 4

Error Yellow LED flashes 1 x: Heater continues operating with risk of low voltage

Accepted Answer

Possible cause: Battery voltage has dropped below 10.4V (gas heater) or 11.5V (diesel heater). Charge battery. For diesel heater, use electrical power from battery sparingly.

Question 5

Error Yellow LED flashes 2 x: Heater not functioning due to low voltage or overvoltage

Accepted Answer

Possible cause: Battery voltage has dropped below 10.0V/10.2V, or risen above 16.4V (overvoltage). Charge the battery, or fit a new one if it's old. For overvoltage, check the battery voltage itself along with whatever's supplying it (e.g. the charger).

Question 6

Error Yellow LED flashes 3 x: Heater stops operating

Accepted Answer

Possible cause: Open window above cowl detected by window switch. Close the window.

Question 7

Error Yellow LED flashes 4 x: The heater faults out after running for an extended period

Accepted Answer

Possible cause: Either it's in summer mode with an empty water container, the warm air outlets are blocked, or the circulated air intake is blocked. Switch the appliance off and let it cool, top up the boiler with water, check each outlet opening individually, and clear any blockage from the circulated air intake.

Question 8

Error Yellow LED flashes 5 x: Heater indicates sensor fault

Accepted Answer

Possible cause: The room temperature sensor or its cable is faulty. Contact an authorised service agent.

Question 9

Error Yellow LED flashes 7 x: Heater indicates control panel fault

Accepted Answer

Possible cause: The control panel or its cable is faulty. Contact an authorised service agent.

Question 10

Error Yellow LED flashes 8 x: Heater indicates short circuit in FrostControl

Accepted Answer

Possible cause: The FrostControl heating element has short-circuited. Unplug the heating element from the electronic control unit and have a specialist fit a replacement.

Question 11

Error Yellow LED flashes 9 x: The heater cuts out roughly 30 seconds after switching on

Accepted Answer

Possible cause: Could be a closed gas cylinder/quick-acting valve, an empty gas cylinder, an iced-up gas pressure regulator, or gas with too high a butane content. Open the gas supply valves, swap in a fresh cylinder, fit an EisEx regulator, or switch to propane.

Question 12

Error Red LED flashes between 1 and 8 times: Heater fault

Accepted Answer

Possible cause: Heater electronics fault. Determine the flashing code and contact an authorised service agent.

Question 13

The green LED stays lit after the heater is switched off

Accepted Answer

Possible cause: This is the after-run cycle, bringing the appliance's temperature down. Nothing's wrong - the after-run cycle switches off by itself within 5 minutes at most.

Question 14

Room heating doesn't respond straight away to an adjustment

Accepted Answer

Possible cause: This is the after-run cycle, bringing the appliance's temperature down. Nothing's wrong - the after-run cycle switches off by itself within 5 minutes at most.

Question 15

Both the green and red LEDs light up once switched on

Accepted Answer

Possible cause: Faulty electronics. Contact an authorised service agent.

Question 16

Error Red LED flashes 6 x: Diesel heater fails to start

Accepted Answer

Possible cause: There isn't enough fuel - the tank wasn't filled enough, has run dry, and/or the vehicle is parked on a slope. Refill the tank, then bleed the fuel line as covered in the initial start-up instructions.

Truma CP E Classic

Technical Specifications

Master Troubleshooting & Diagnostics Matrix

Also Fitted In

Error Code / Indicator	Symptom / Meaning	Possible Cause	Step-by-Step DIY Fix	Suggested Actions
`N/A`	None of the LEDs light up, even with the appliance switched on and getting its operating voltage	The automatic restart lock has kicked in, e.g. following a power cut	Clear the fault by switching off, leaving it 5 seconds, then switching back on.	DIY Safe
`N/A`	Nothing lights up when it's switched on	No operating voltage or appliance/vehicle fuse defective	Check the 12V battery voltage and charge if needed, check every electrical plug connection, and check/replace the appliance's or vehicle's fuse.	DIY Safe
`N/A`	The green LED lights up once switched on, but the heater doesn't run	The control panel's temperature setting is below the current room temperature.	Turn the temperature setting up at the control panel.	DIY Safe
`Yellow LED flashes 1 x`	Heater continues operating with risk of low voltage	Battery voltage has dropped below 10.4V (gas heater) or 11.5V (diesel heater)	Charge battery. For diesel heater, use electrical power from battery sparingly.	DIY Safe
`Yellow LED flashes 2 x`	Heater not functioning due to low voltage or overvoltage	Battery voltage has dropped below 10.0V/10.2V, or risen above 16.4V (overvoltage)	Charge the battery, or fit a new one if it's old. For overvoltage, check the battery voltage itself along with whatever's supplying it (e.g. the charger).	DIY Safe
`Yellow LED flashes 3 x`	Heater stops operating	Open window above cowl detected by window switch	Close the window.	DIY Safe
`Yellow LED flashes 4 x`	The heater faults out after running for an extended period	Either it's in summer mode with an empty water container, the warm air outlets are blocked, or the circulated air intake is blocked	Switch the appliance off and let it cool, top up the boiler with water, check each outlet opening individually, and clear any blockage from the circulated air intake.	DIY Safe
`Yellow LED flashes 5 x`	Heater indicates sensor fault	The room temperature sensor or its cable is faulty	Contact an authorised service agent.	Professional Intervention Required
`Yellow LED flashes 7 x`	Heater indicates control panel fault	The control panel or its cable is faulty	Contact an authorised service agent.	Professional Intervention Required
`Yellow LED flashes 8 x`	Heater indicates short circuit in FrostControl	The FrostControl heating element has short-circuited	Unplug the heating element from the electronic control unit and have a specialist fit a replacement.	DIY Check / Tech Fallback
`Yellow LED flashes 9 x`	The heater cuts out roughly 30 seconds after switching on	Could be a closed gas cylinder/quick-acting valve, an empty gas cylinder, an iced-up gas pressure regulator, or gas with too high a butane content	Open the gas supply valves, swap in a fresh cylinder, fit an EisEx regulator, or switch to propane.	DIY Safe
`Red LED flashes between 1 and 8 times`	Heater fault	Heater electronics fault	Determine the flashing code and contact an authorised service agent.	Professional Intervention Required
`N/A`	The green LED stays lit after the heater is switched off	This is the after-run cycle, bringing the appliance's temperature down	Nothing's wrong - the after-run cycle switches off by itself within 5 minutes at most.	DIY Safe
`N/A`	Room heating doesn't respond straight away to an adjustment	This is the after-run cycle, bringing the appliance's temperature down	Nothing's wrong - the after-run cycle switches off by itself within 5 minutes at most.	DIY Safe
`N/A`	Both the green and red LEDs light up once switched on	Faulty electronics	Contact an authorised service agent.	Professional Intervention Required
`Red LED flashes 6 x`	Diesel heater fails to start	There isn't enough fuel - the tank wasn't filled enough, has run dry, and/or the vehicle is parked on a slope	Refill the tank, then bleed the fuel line as covered in the initial start-up instructions.	DIY Safe