BoilerFaultCodesYour boiler has lost power because an internal electrical safety fuse has blown, likely caused by a faulty component or wiring issue.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Examine fan harness for short circuits. If fuse blows without harness, replace PCB 40.
What causes this fault?
This fault occurs when an electrical surge or short circuit triggers a safety fuse on the main control board to prevent further damage. The most common reason is a failing internal component, such as the fan or the wiring connected to it, drawing too much power or touching the boiler's metal casing. This causes the boiler to lose power immediately as a protective measure.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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