BoilerFaultCodesYour boiler has detected an electrical fault with the sensor that monitors your hot water tank temperature, preventing it from heating your water correctly.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Tank NTC short circuit
What causes this fault?
This fault occurs when the electrical signal from the hot water cylinder's temperature sensor reaches an impossibly high level, usually because the internal wiring has failed or touched together. The most common reason is that the sensor has developed a 'short circuit' due to age or moisture, or the delicate wires connecting it to the boiler have been pinched or damaged.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
Find a Gas Safe engineer
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A boiler cover plan would cover faults like F.13 — 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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