BoilerFaultCodesYour boiler's temperature sensors are giving conflicting readings and cannot accurately tell how hot the water is.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Flow/return sensor calibration error
What causes this fault?
This fault occurs when the internal brain of the boiler notices that the two sensors measuring the water temperature are reporting figures that are too far apart to be realistic. It is usually caused by an electrical failure within the sensors themselves or a poor connection in the wiring that links them to the main control board. Because the boiler can no longer safely tell 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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