Power Supply Fault
Grant
Local Power or Fuse Failure
The boiler display is blank, with no lights or response, but other electrical circuits in the property are working.
Advertisements
Possible Causes
Blown 3A fuse in the fused spur, Tripped MCB for the boiler circuit, Loose live/neutral connection at the boiler, Internal fuse on the PCB blown
How to Fix / Troubleshooting
Safety: Only check fuses if you are competent. Always isolate power at the consumer unit if in doubt.
User checks:
- Check the fused spur supplying the Grant boiler; replace the fuse with the correct rating (usually 3A) if it is blown.
- Ensure the spur switch is ON and any neon indicator is lit.
- Check the consumer unit for a tripped MCB or RCD and reset if appropriate.
Engineer checks:
- Verify 230 V at the boiler terminals.
- Inspect and tighten terminal connections inside the boiler.
- Check any internal PCB fuses and replace with an identical type and rating if it is blown, after identifying the cause.
Advertisements
Repair Difficulty
Easy
2/5
Advertisements