BoilerFaultCodesYour boiler has detected an issue with the sensor that monitors the water temperature inside your unit, which has caused it to stop running 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: Boiler internal fault (primary sensor fault)
What causes this fault?
This fault occurs when the boiler's main temperature sensor fails to send a reliable electronic signal to the control board. It is usually caused by the internal components of the sensor wearing out over time or the electrical connections becoming loose or corroded. Because the boiler no longer knows how hot the water is, it shuts down immediately to prevent the system from overheating.
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 05 — no call-out fees, no surprises.
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