BoilerFaultCodesYour boiler's internal computer has lost its programming or was replaced and hasn't been set up yet, meaning it doesn't know how to operate your specific heating system.
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 loses the specific software instructions required to run your heating system safely. The most common reason is that a new circuit board has been installed but not yet programmed, or a power surge has wiped the memory of the existing component.
This fault is often seen following summer storms, as power surges from lightning strikes can scramble the sensitive electronic memory of the boiler's control board.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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A boiler cover plan would cover faults like F 09 L 09 — 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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