How much does it cost to fix boiler error code ON OFF ON?

Typical repair cost for the boiler ON OFF ON fault is £100-350 including labour.

ON OFF ON High

Boiler Fault Code ON OFF ON

Also written as ONOFFON — same fault.

Reviewed by the BoilerFaultCodes Editorial Team Last reviewed 27 April 2026

Fault code ON OFF ON appears across 2 boiler brands and 27 models. The exact meaning varies by manufacturer — pick your boiler brand below to see the model-specific fix.

Most common meaning Your boiler has tried to start up several times but failed to light the flame, causing it to shut down for safety. (As reported on Baxi Solo)

Pick your boiler brand for the ON OFF ON fix

Baxi ON OFF ON 23 models Potterton ON OFF ON 4 models

Source

Information for the ON OFF ON fault code is sourced from the official service / installation manual for each model that displays it. Read more about how we source fault codes →

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 27 April 2026