Boiler displays E18, often after a power surge or lightning strike; boiler may be completely unresponsive or partially functional.
Safety Warning
This repair may involve working with high voltage components or water connections. Always unplug the appliance before removing any panels.
If you are not confident in your ability to perform this repair safely, we strongly recommend contacting a professional technician.
Possible Causes
How to Fix / Troubleshooting
Safety first: Isolate the boiler from the mains before inspecting electrical connections.
User-level checks:
- Check that other electrical appliances in the property are working normally.
- Reset the boiler by turning off the mains for several minutes.
Technical checks (qualified personnel):
- Verify mains voltage at the boiler terminals with a multimeter.
- Inspect the internal fuse(s) on the PCB and replace only with identical rated fuses if blown.
- Check for visible damage or burning on the PCB; if present, replace the board.
- If mains supply is unstable, recommend installation of a voltage stabiliser or surge protection.
After repair, confirm that the boiler powers up correctly and that all functions operate as expected.
Repair Difficulty
Required Part
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