BoilerFaultCodesYour boiler's internal sensor has stopped correctly monitoring the water temperature as it leaves the unit, preventing it from heating up properly.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Flow sensor error
What causes this fault?
This fault occurs when the boiler's internal thermometer, which measures the water temperature as it leaves the unit, sends an incorrect or missing signal to the control board. The most common reason is that the sensor has physically failed due to age or wear, though loose or damaged electrical wiring can also prevent the sensor from communicating correctly.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
Find a Gas Safe engineer
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A boiler cover plan would cover faults like F10 — no call-out fees, no surprises.
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