BoilerFaultCodesYour boiler has lost communication with one of its internal sensors, meaning it cannot accurately monitor temperatures to run safely.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Sensor defect or improper contacts and connections.
What causes this fault?
This fault occurs when the boiler's control board can no longer read the temperature signals from the internal sensors. The most common reason is a physical failure of the thermistor component itself, or loose wiring connections caused by the natural vibrations of the boiler over time.
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 24 — no call-out fees, no surprises.
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