Keston No Power / Dead Boiler

Boiler will not start at all, no lights or display

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

Blown fuse in spur, Tripped circuit breaker, Loose mains wiring, Failed main PCB

How to Fix / Troubleshooting

Safety: Do not open electrical enclosures unless you are competent. Isolate power before any inspection.

User actions:

Check that the boiler's fused spur is switched on and that the fuse has not blown (typically 3A).
Inspect the consumer unit for tripped breakers or RCDs and reset if appropriate.
If power is present at the spur but the boiler is still dead, contact an engineer.

Engineer actions:

Verify voltage at the boiler mains terminal block and check for correct polarity and earth.
Inspect internal fuses on the Keston PCB and replace with correct type if blown, investigating the cause.
Check for signs of PCB damage (burn marks, bulging components) and replace the PCB if necessary.

Repair Difficulty

Medium 3/5

Required Part

Main Control PCB

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