Master Troubleshooting & Diagnostics Matrix
| Error Code / Indicator | Symptom / Meaning | Possible Cause | Step-by-Step DIY Fix | Suggested Actions |
|---|---|---|---|---|
N/A | Heating ignition sparks can't be heard, or are more than a second apart | — | Fit a new battery in the automatic ignitor. | DIY Safe |
Recommended partAffiliate linksView partHideHobby and Truma specify a temperature-resistant (+70°C), leakproof AA (Mignon) battery for the ignitor. We couldn't find a widely sold AA rated to +70°C - this lithium AA is the highest-rated common option (+60°C, versus about +50-55°C for standard alkaline). AA lithium (rated to +60°C)Energizer Ultimate Lithium AA Batteries (4 Pack)~£6.99 for 44.6★ (26,000+ ratings), sold by Amazon - lithium AA, rated -40°C to +60°C View on Amazon → | ||||
N/A | Boiler control panel's red LED comes on or blinks | — | Carefully clean fan wheel with a brush. | DIY Safe |
N/A | FrostControl valve opens automatically and the button pops out | The temperature at the drain valve is under approx. 3 degrees C | This is normal automatic protection - the boiler's contents drain away through the drain outlet on their own; no action needed unless you want to prevent it, e.g. by keeping the area heated. Once the temperature at the valve rises back above about 7°C you can close it again by hand to refill the boiler. | DIY Safe |