BoilerFaultCodesYour boiler has stopped working because one of its internal sensors is failing to monitor the temperature of the water returning to the unit.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Return gas sensor failure
What causes this fault?
This fault occurs when the boiler's control board loses communication with the sensor that measures the temperature of the water coming back from your radiators. The most common reason is that the sensor itself has developed an electrical fault or the wiring connecting it to the main controller has become loose or damaged.
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 PP4 — 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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