High
C. (4) on Potterton Kingfisher 2

Your boiler recognizes the pilot light is on, but it is failing to trigger the main heating flame because it is struggling to accurately detect your home's temperature.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

Call an engineer soon

Book a Gas Safe engineer within 24 to 48 hours. Your boiler may be unsafe or could break down completely if left.

Technical description

Main burner fails to light, pilot burning - Thermostat out of calibration or faulty.

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.

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