BoilerFaultCodesYour boiler's internal computer has lost its settings or suffered a technical failure and can no longer control the 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: Printed circuit board (PCB) unconfigured or fault
What causes this fault?
This fault occurs when the boiler's main control board loses its identity or suffers an internal electronic failure, meaning it can no longer communicate with the rest of the components. The most common reason is a glitch in the software memory or a physical defect in the plug-in configuration chip that tells the board exactly which model of boiler it is controlling.
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.
Gas Safe Register →Protect yourself from future repair bills
A boiler cover plan would cover faults like F9 — 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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