How to Fix / Troubleshooting

Safety: All gas valve work must be carried out by a Gas Safe registered engineer. Isolate gas and power before starting.

User checks:

Confirm gas supply to the property is available and other gas appliances operate normally.
Do not attempt to adjust or tap the gas valve.

Engineer checks:

Check the electrical connector on the Keston gas valve for secure fit and no signs of overheating.
Measure resistance of the gas valve coil(s) and compare with manufacturer specifications; replace the valve if open or shorted.
During ignition attempt, measure control voltage at the gas valve terminals; if absent, suspect PCB fault.
After replacement, commission the boiler with a flue gas analyser and adjust gas valve settings as per Keston combustion instructions.

Boiler shows E13, fan runs but ignition sequence does not start

Possible Causes