BoilerFaultCodesYour boiler has stopped working because a sensor that monitors the temperature of the water returning to the unit has developed an electrical fault.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Return NTC short circuit
What causes this fault?
This fault occurs when the sensor that monitors cooled water returning to the boiler develops an internal electrical failure. The most common reason is that the sensor has suffered an electrical short circuit, often due to moisture ingress or general wear and tear over time. When this happens, the boiler can no longer safely calculate the temperature difference across the heat exchanger, so it shuts 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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A boiler cover plan would cover faults like F.11 — 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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