How much does it cost to fix boiler error code L43?

Typical repair cost for the boiler L43 fault is £450-950 including labour.

L43 High

Boiler Fault Code L43

Reviewed by the BoilerFaultCodes Editorial Team Last reviewed 27 April 2026

Fault code L43 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 heat pump has stopped working because its internal computer board is having trouble communicating with the compressor system. (As reported on Ideal HP290)

Pick your boiler brand for the L43 fix

Ideal L43 1 model

Source

Information for the L43 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