5 fault codes with plain-English explanations, severity ratings, DIY guidance, and repair cost estimates.
This boiler uses LED flash patterns
Count the flashes in one repeating group before the pause. That number is your fault code. Do not reset until you have noted it. How to read fault codes →
Tap any card for details
Your boiler's fan isn't starting or spinning at the correct speed, which prevents the boiler from safely lighting.
Your boiler has detected a problem with the temperature sensor that monitors your radiators, meaning it cannot safely gauge how hot the water is.
Your boiler has stopped working because water is not moving through the system properly, which could be caused by a blockage, a faulty pump, or trapped air.
Your boiler has shut down because it triggered a safety sensor or overheated, meaning it needs to cool down and be inspected.
Your boiler has failed to light the gas to create a flame, causing the system to shut down for safety.
Not faults — these are normal operating states. Tap to expand.
BoilerFaultCodes