BoilerFaultCodesYour boiler's internal temperature sensors are giving conflicting readings, causing the system to stop working 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: Sensor: Flow or return sensor out of calibration
What causes this fault?
This fault occurs when the boiler's control board detects that the temperature readings from the flow and return pipes don't match up as they should. The most common reason is that one of the internal sensors has drifted out of its correct electrical range or has developed a physical defect, making it impossible for the boiler to safely monitor how much heat it is producing.
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 1 — no call-out fees, no surprises.
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