How much does it cost to fix boiler error code 335?

Typical repair cost for the boiler 335 fault is £150-250 including labour.

335 High

Boiler Fault Code 335

Reviewed by the BoilerFaultCodes Editorial Team Last reviewed 7 July 2026

Fault code 335 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 has lost connection to a critical internal component, meaning it cannot properly monitor its own temperature and has shut down to stay safe. (As reported on ECA FELiS FL 50 HM)

Pick your boiler brand for the 335 fix

ECA 335 1 model

Source

Information for the 335 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