BoilerFaultCodesYour boiler's internal computer brain either isn't set up correctly or has developed a technical hardware fault, preventing the unit from starting.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: PCB UNCONFIGURED OR FAULTY
What causes this fault?
This fault occurs when the boiler's main control board has lost its identity and no longer knows which specific model it is supposed to be operating. The most common reason is a technical communication failure between the internal computer chip and the plug-in hardware key that stores the boiler's settings.
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 L8 — no call-out fees, no surprises.
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