C7 High

Boiler Fault Code C7

Reviewed by the BoilerFaultCodes Editorial Team Last reviewed

Fault code C7 appears across 4 boiler brands and 13 models. The exact meaning varies by manufacturer — pick your boiler brand below to see the model-specific fix.

Most common meaning Your boiler’s internal electronic brain is having trouble communicating with the compressor pump, meaning your heating and hot water have stopped working. (As reported on Ideal HP290)

Pick your boiler brand for the C7 fix

Ideal C7 1 model Remeha C7 2 models Viessmann C7 8 models Worcester Bosch C7 2 models

Source

Information for the C7 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