High
Flow Thermistor on Baxi Combi 80e

Your boiler has detected a problem with the temperature sensor that monitors the water leaving the unit, meaning it cannot safely regulate heat.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

Call an engineer soon

Book a Gas Safe engineer within 24 to 48 hours. Your boiler may be unsafe or could break down completely if left.

Technical description

LED 1: Flash, LED 2: On, LED 3: On, LED 4: Off (Go to Flow Thermistor section of the fault finding instructions)

Engineer required

This is a high severity fault. Stop using the boiler and call a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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