How much does it cost to fix boiler error code 1A?

Typical repair cost for the boiler 1A fault is £120-450 including labour.

1A High

Boiler Fault Code 1A

Reviewed by the BoilerFaultCodes Editorial Team Last reviewed 7 July 2026

Fault code 1A appears across 2 boiler brands and 5 models. The exact meaning varies by manufacturer — pick your boiler brand below to see the model-specific fix.

Most common meaning Your boiler has shut down because it is struggling to discharge exhaust fumes safely or is detecting a significant lack of air flow. (As reported on Viessmann Vitodens 200-W)

Pick your boiler brand for the 1A fix

Ravenheat 1A 1 model Viessmann 1A 4 models

Source

Information for the 1A 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