How much does it cost to fix boiler error code 345?

Typical repair cost for the boiler 345 fault is £150-300 including labour.

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Boiler Fault Code 345

Reviewed by the BoilerFaultCodes Editorial Team Last reviewed 7 July 2026

Fault code 345 appears across 3 boiler brands and 6 models. The exact meaning varies by manufacturer — pick your boiler brand below to see the model-specific fix.

Most common meaning Your boiler is failing to detect any heat being produced after the burner lights, which suggests the internal water circulation has stopped or the temperature sensors are not working correctly. (As reported on Worcester Bosch Greenstar 28CDi)

Pick your boiler brand for the 345 fix

ECA 345 1 model Viessmann 345 1 model Worcester Bosch 345 4 models

Source

Information for the 345 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 7 July 2026