BoilerFaultCodesYour boiler has lost power or detected an internal safety fault that is preventing it from firing up.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: System or boiler sensors have detected a fault. Contact your service engineer.
What causes this fault?
This fault occurs when the boiler's internal safety controls detect that the system has either overheated or is failing to move air and waste gases safely through the flue. The most common reason is a component failure, such as a stuck pressure switch or a tripped safety thermostat, which forces the boiler to shut down to prevent damage. Because all status lights are off while the main power light remains on, it indicates the boiler has reached a dead stop and cannot continue its ignition sequence.
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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