How much does it cost to fix boiler error code Flow Thermistor Fault?

Typical repair cost for the boiler Flow Thermistor Fault fault is £90-180 including labour.

Flow Thermistor Fault High

Boiler Fault Code Flow Thermistor Fault

Also written as FLOWTHERMISTORFAULT — same fault.

Reviewed by the BoilerFaultCodes Editorial Team Last reviewed 27 April 2026

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

Most common meaning Your boiler has detected that a temperature sensor is not communicating correctly, which has caused the system to stop working to prevent overheating. (As reported on Ideal Logic Code Combi ESP1)

Pick your boiler brand for the Flow Thermistor Fault fix

Ideal Flow Thermistor Fault 5 models Johnson Starley Flow Thermistor Fault 1 model Potterton Flow Thermistor Fault 2 models

Source

Information for the Flow Thermistor Fault 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