BoilerFaultCodesYour boiler has stopped working because its internal thermometers are giving conflicting readings and believe they have been fitted to the wrong pipes.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Temperature sensors incorrectly installed
What causes this fault?
This fault occurs when the boiler's internal sensors detect that the flow and return pipes are heating up in the wrong order or at unexpected rates. The most common reason is that the temperature sensors have been physically clipped onto the wrong pipes during a repair, or the wiring harness has developed a fault that sends conflicting signals to 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.85 — 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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