BoilerFaultCodesYour boiler has detected a problem with the temperature sensor that monitors the water returning from your radiators, causing the system to shut down for safety.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Return Thermistor
What causes this fault?
This fault occurs when the sensor responsible for measuring the temperature of the water flowing back into the boiler becomes faulty or loses its connection. The most common reason is that the sensor has internal electrical failure or the wiring has become loose, meaning the boiler can no longer safely monitor heat levels. Because the control board cannot verify the water temperature, it shuts the system down as a safety precaution.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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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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