Your boiler has detected that the internal sensor responsible for monitoring the temperature of your heating system has developed a fault.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Fault on Central Heating Sensor
What causes this fault?
This fault occurs when the boiler's control board loses communication with the temperature sensor or receives an incorrect reading. The most common reason is that the sensor has physically degraded over time or the electrical wire connecting it to the main system has become loose or corroded.
This fault often appears when the heating is first turned on after summer, as the sensor may struggle to respond correctly after a long period of inactivity.
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 28 — no call-out fees, no surprises.
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