How much does it cost to fix boiler error code 1 2 3 4?

Typical repair cost for the boiler 1 2 3 4 fault is £120-250 including labour.

1 2 3 4 High

Boiler Fault Code 1 2 3 4

Also written as 1234 — same fault.

Reviewed by the BoilerFaultCodes Editorial Team Last reviewed 7 July 2026

Fault code 1 2 3 4 appears across 1 boiler brand and 2 models. The exact meaning varies by manufacturer — pick your boiler brand below to see the model-specific fix.

Most common meaning Your boiler has failed to ignite because the internal connection responsible for detecting or starting the flame has stopped working correctly. (As reported on Halstead Eden CBX/SBX)

Pick your boiler brand for the 1 2 3 4 fix

Halstead 1 2 3 4 2 models

Source

Information for the 1 2 3 4 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