11 fault codes with plain-English explanations, severity ratings, DIY guidance, and repair cost estimates.
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Your boiler has lost power to its internal electronics, likely caused by a safety fuse blowing or an electrical fault inside the unit.
Your boiler has likely experienced an internal electrical fault or a component failure that has caused a safety fuse on the main control board to blow.
Your boiler is struggling to start up properly because the main internal computer is failing to control the fan correctly.
Your boiler's electronic control system is stuck in an error state while trying to fire up the main burner, meaning it cannot safely provide heating or hot water.
Your boiler has detected an electrical supply issue, likely caused by a tripped switch, a blown fuse, or a temporary power failure.
Your boiler has detected an internal electrical communication fault which is preventing it from starting up safely.
Your boiler is failing to light the small internal flame needed to start the main burner, which means your heating and hot water will not work.
Your boiler has lost power because of an electrical issue or a blown fuse inside the control unit.
Your boiler has switched itself off because it has either become too hot or the water pressure in the system has dropped too low.
Your boiler has stopped working because it cannot safely confirm that the fan is clearing exhaust gases from the system.
Your boiler is attempting to start but cannot successfully light or detect a steady flame, so it has shut down for safety.
Not faults — these are normal operating states. Tap to expand.
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BoilerFaultCodes