BoilerFaultCodesYour boiler has detected an electrical fault with the sensor that monitors 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 NTC short circuit
What causes this fault?
This fault occurs when the electrical connection within the return pipe sensor breaks down, creating a 'short circuit' that sends an incorrect signal to the boiler's computer. The most common reason is internal wear and tear of the sensor itself, though it can also be triggered by water leaking onto the electrical cables or a fault in the main control board.
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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