Your boiler has detected a technical fault with the sensor that monitors water returning to the unit, causing the system to shut down 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: Temp.sensor fault: Short-circuit in return temperature sensor.
What causes this fault?
This fault occurs when the boiler’s internal computer receives an incorrect electrical signal from the sensor that monitors water coming back from your radiators. The most common reason is that the sensor has developed an internal electrical short or the protective coating on the connecting wires has worn away, causing the system to shut down for safety. In some cases, water ingress or moisture near the electrical connections can also trigger this specific error.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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A boiler cover plan would cover faults like 3 2. — 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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