Your boiler has detected an issue with its internal sensors and has stopped running to prevent any damage or incorrect temperature readings.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: The diagnostics will indicate the nature of the fault to assist a speedy and effective repair
What causes this fault?
This fault occurs when the boiler's internal sensors stop communicating correctly with the main control board. It is usually caused by an electrical failure within the sensor itself or a loose connection in the wiring that prevents the boiler from safely monitoring water temperature. Because the boiler cannot tell how hot the water is getting, it shuts down as a safety precaution.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
Find a Gas Safe engineer
Search the official register for a qualified engineer in your area.
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