How much does it cost to fix boiler error code 705?

Typical repair cost for the boiler 705 fault is £180-£450 including labour.

705 High

Boiler Fault Code 705

Reviewed by the BoilerFaultCodes Editorial Team Last reviewed 27 April 2026

Fault code 705 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 is having trouble communicating with the internal electronic controls, meaning it cannot process instructions to heat your home. (As reported on Ariston Alteas One)

Pick your boiler brand for the 705 fix

Ariston 705 1 model

Source

Information for the 705 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