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

Typical repair cost for the boiler internal error fault is £250-550 including labour.

internal error High

Boiler Fault Code internal error

Also written as INTERNALERROR — same fault.

Reviewed by the BoilerFaultCodes Editorial Team Last reviewed 27 April 2026

Fault code internal error appears across 1 boiler brand and 1 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 computer brain is having trouble communicating with its power supply, preventing the system from starting up. (As reported on Worcester Bosch Greenstar i)

Pick your boiler brand for the internal error fix

Worcester Bosch internal error 1 model

Source

Information for the internal error 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