How much does it cost to fix boiler error code ER 8?

Typical repair cost for the boiler ER 8 fault is £120-180 including labour.

ER 8 High

Boiler Fault Code ER 8

Also written as ER8 — same fault.

Reviewed by the BoilerFaultCodes Editorial Team Last reviewed 27 April 2026

Fault code ER 8 appears across 2 boiler brands and 3 models. The exact meaning varies by manufacturer — pick your boiler brand below to see the model-specific fix.

Most common meaning Your boiler is currently unable to correctly measure the temperature of the water it is heating, so it has stopped providing hot water to keep the system safe. (As reported on Ferroli Xignal)

Pick your boiler brand for the ER 8 fix

Ferroli ER 8 1 model Vaillant ER 8 2 models

Source

Information for the ER 8 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