How much does it cost to fix boiler error code I3?

Typical repair cost for the boiler I3 fault is £60-120 including labour.

I3 High

Boiler Fault Code I3

Reviewed by the BoilerFaultCodes Editorial Team Last reviewed 27 April 2026

Fault code I3 appears across 2 boiler brands and 2 models. The exact meaning varies by manufacturer — pick your boiler brand below to see the model-specific fix.

Most common meaning Your boiler is not receiving any electrical power, which is why the lights are off and it isn't working. (As reported on Ideal Classic FF)

Pick your boiler brand for the I3 fix

Ideal I3 1 model Worcester Bosch I3 1 model

Source

Information for the I3 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