How much does it cost to fix boiler error code 40-70 (ll-ll)?

Typical repair cost for the boiler 40-70 (ll-ll) fault is £120-250 including labour.

40-70 (ll-ll) High

Boiler Fault Code 40-70 (ll-ll)

Also written as 4070LLLL — same fault.

Reviewed by the BoilerFaultCodes Editorial Team Last reviewed 27 April 2026

Fault code 40-70 (ll-ll) appears across 1 boiler brand and 4 models. The exact meaning varies by manufacturer — pick your boiler brand below to see the model-specific fix.

Most common meaning Your boiler is struggling to stay lit and has failed to restart after several attempts to create a steady flame. (As reported on Ariston Genus 30 Plus)

Pick your boiler brand for the 40-70 (ll-ll) fix

Ariston 40-70 (ll-ll) 4 models

Source

Information for the 40-70 (ll-ll) 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