BoilerFaultCodesYour boiler has detected a communication problem between its internal sensors or a fault in its main control board, 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: Electronics / NTC error
What causes this fault?
This fault occurs when the boiler's internal computer receives conflicting information from its temperature sensors or detects a short circuit in the wiring. The most common reason is that either the flow or return sensors have failed, or the main circuit board can no longer accurately process the signals it is receiving.
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.64 — 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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