BoilerFaultCodesYour boiler's internal computer brain is not communicating correctly with the rest of the unit and needs to be officially set up.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Unconfigured PCB
What causes this fault?
This fault occurs when the boiler's main control board has lost its identity or was never properly told which specific model it is installed in. The most common reason is that a new circuit board has been fitted but not yet programmed with the correct software code, or a sudden power surge has wiped the board's internal memory.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
Find a Gas Safe engineer
Search the official register for a qualified engineer in your area.
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A boiler cover plan would cover faults like L09 — 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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