How much does it cost to fix boiler error code LED 1 & 2 Simultaneous Lit?

Typical repair cost for the boiler LED 1 & 2 Simultaneous Lit fault is £150-300 including labour.

LED 1 & 2 Simultaneous Lit High

Boiler Fault Code LED 1 & 2 Simultaneous Lit

Also written as LED12SIMULTANEOUSLIT — same fault.

Reviewed by the BoilerFaultCodes Editorial Team Last reviewed 7 July 2026

Fault code LED 1 & 2 Simultaneous Lit 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 failing to start because it cannot confirm that the internal fan is moving air correctly to safely vent exhaust gases. (As reported on Glow-worm Micron 30ff)

Pick your boiler brand for the LED 1 & 2 Simultaneous Lit fix

Glow-worm LED 1 & 2 Simultaneous Lit 1 model

Source

Information for the LED 1 & 2 Simultaneous Lit 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