How much does it cost to fix boiler error code 9A?

Typical repair cost for the boiler 9A fault is £90-180 including labour.

9A Low

Boiler Fault Code 9A

Reviewed by the BoilerFaultCodes Editorial Team Last reviewed 27 April 2026

Fault code 9A appears across 3 boiler brands and 11 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 communication with the temperature sensor that monitors the outdoor solar panels or the system collector, meaning it cannot accurately manage heat levels for those components. (As reported on Viessmann Vitodens 200)

Pick your boiler brand for the 9A fix

Ideal 9A 1 model Viessmann 9A 7 models Worcester Bosch 9A 3 models

Source

Information for the 9A 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