BoilerFaultCodesYour boiler has detected that a internal sensor responsible for monitoring water temperature returning to the unit is faulty or disconnected.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Return sensor (43)
What causes this fault?
This fault occurs when the boiler's control board loses communication with the sensor that monitors water temperature coming back from your radiators. The most common reason is that the internal sensor has developed an electrical failure or the wiring connecting it to the main computer has become loose or damaged. Because the boiler can no longer safely track how hot the water is, it shuts down to prevent overheating.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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