How much does it cost to fix boiler error code A18?

Typical repair cost for the boiler A18 fault is £280-450 including labour.

A18 High

Boiler Fault Code A18

Reviewed by the BoilerFaultCodes Editorial Team Last reviewed 27 April 2026

Fault code A18 appears across 3 boiler brands and 7 models. The exact meaning varies by manufacturer — pick your boiler brand below to see the model-specific fix.

Most common meaning Your boiler's internal computer memory is not communicating correctly with the main control board, preventing the system from starting. (As reported on Vokera Condexa Pro)

Pick your boiler brand for the A18 fix

Ariston A18 5 models Potterton A18 1 model Vokera A18 1 model

Source

Information for the A18 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