BoilerFaultCodesYour boiler's internal computer has encountered an electronic error and is unable to communicate with its controls to provide heat.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: internal failure - electronic
What causes this fault?
This fault occurs when the boiler's main control board experiences a critical hardware failure and can no longer process instructions. It is usually caused by a component on the circuit board wearing out over time or being damaged by a sudden electrical surge. Because the 'brain' of the boiler has failed, it can no longer safely manage the gas valve or ignition process.
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 400 — no call-out fees, no surprises.
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