BoilerFaultCodesYour boiler is struggling to accurately measure the water temperature, causing it to shut down to prevent overheating.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Flow and/or Return thermistor fault
What causes this fault?
This fault occurs when the boiler's control board receives conflicting or incorrect temperature signals from the sensors on the main pipes. It usually happens because these sensors have drifted out of their correct calibration or the wiring connecting them has degraded. As a safety precaution, the boiler shuts down because it can no longer accurately monitor if the water is getting too hot.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
Find a Gas Safe engineer
Search the official register for a qualified engineer in your area.
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A boiler cover plan would cover faults like F72 — no call-out fees, no surprises.
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