BoilerFaultCodesYour boiler has lost its connection to the sensor that monitors heating temperature, so it has stopped running as a safety precaution.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Central heating thermistor unplugged
What causes this fault?
This fault occurs when the boiler's internal computer loses communication with the sensor that monitors the temperature of the water sent to your radiators. The most common cause is the sensor itself failing due to age or internal wear, though it can also be triggered by a loose or damaged wiring connection inside the unit.
This fault is often more frequent during the autumn and winter months when the boiler is suddenly under higher demand after being inactive during the summer.
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 F19 — no call-out fees, no surprises.
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Could it be time for a new boiler?
If repair costs are adding up, a new energy-efficient boiler could be the smarter long-term choice.
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