BoilerFaultCodesTechnical 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.
Engineer required
This is a high severity fault. Stop using the boiler and call a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.