How much does it cost to fix boiler error code LED 4?

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

LED 4 High

Boiler Fault Code LED 4

Also written as LED4 — same fault.

Reviewed by the BoilerFaultCodes Editorial Team Last reviewed 31 August 2026

Fault code LED 4 appears across 3 boiler brands and 9 models. The exact meaning varies by manufacturer — pick your boiler brand below to see the model-specific fix.

Most common meaning Your boiler is signalling an electrical wiring issue or a faulty thermostat connection, which is preventing it from communicating correctly to start your heating or hot water. (As reported on Ideal RD2)

Pick your boiler brand for the LED 4 fix

Ferroli LED 4 3 models Ideal LED 4 3 models Myson LED 4 3 models

Source

Information for the LED 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 31 August 2026