BoilerFaultCodesYour boiler has lost electrical power, which is usually caused by an issue with the mains supply or a blown internal fuse.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Fault with mains supply or PCB fuse
What causes this fault?
This fault occurs when the boiler is not receiving the electrical power it needs to operate, causing the control panel to go dark except for the error light. The most common reason is a blown fuse on the main circuit board or a tripped switch in your home's fuse box, often triggered by a sudden power surge or a failing internal component. In some cases, it can simply be that the external power switch for the boiler has been accidentally turned off.
This fault is slightly more common during the winter months when power grids are under higher load or during stormy weather, as electrical surges and lightning strikes are more likely to blow sensitive internal fuses.
DIY fix possible
Check if other appliances in the house are working to rule out a general power cutEnsure the boiler's fused spur switch (usually near the boiler) is turned onCheck your home's main consumer unit (fuse box) to see if a circuit breaker has tripped
Find a Gas Safe engineer
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