How much does it cost to fix boiler error code 1 2?

Typical repair cost for the boiler 1 2 fault is £0-£120 including labour.

1 2 High

Boiler Fault Code 1 2

Also written as 12 — same fault.

Reviewed by the BoilerFaultCodes Editorial Team Last reviewed 31 August 2026

Fault code 1 2 appears across 4 boiler brands and 6 models. The exact meaning varies by manufacturer — pick your boiler brand below to see the model-specific fix.

Most common meaning Your boiler has stopped working because the water pressure inside the system has dropped too low to operate safely. (As reported on Glow-worm EnergySaver Combi)

Pick your boiler brand for the 1 2 fix

Baxi 1 2 3 models Glow-worm 1 2 1 model Remeha 1 2 1 model Saunier Duval 1 2 1 model

Source

Information for the 1 2 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 31 August 2026