BoilerFaultCodesYour boiler's main control board is struggling to identify which specific model it is due to an electrical communication error.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Short circuit on coding resistor
What causes this fault?
This fault occurs when the boiler's main control board loses the ability to read a small electronic component that tells it which model size it is managing. The most common reason is a signal failure caused by a short circuit in the wiring or a total failure of the main printed circuit board itself.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
Find a Gas Safe engineer
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A boiler cover plan would cover faults like F.42 — no call-out fees, no surprises.
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