BoilerFaultCodesYour boiler is temporarily confused by its internal software settings and cannot start up correctly.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Temporary error- incorrect configuration settings C1/C2.
What causes this fault?
This fault occurs when the boiler's internal computer becomes confused about which specific model it is supposed to be. It is usually caused by a glitch in the software or a communication error between the electronic components after a power surge or a component failure. Because the boiler cannot confirm its own identity and safety parameters, it shuts down as a protective measure.
DIY fix possible
Locate the selector switch or reset button on the front of the boiler.Turn the switch to the 'R' (Reset) position and hold for at least 5 seconds.Wait for the boiler to restart; if the code repeats, a Gas Safe engineer must reconfigure the internal board.
Find a Gas Safe engineer
Search the official register for a qualified engineer in your area.
Gas Safe Register →Protect yourself from future repair bills
A boiler cover plan would cover faults like H.02 – .03 — no call-out fees, no surprises.
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Could it be time for a new boiler?
If repair costs are adding up, a new energy-efficient boiler could be the smarter long-term choice.
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