BoilerFaultCodesYour boiler's internal thermometer has stopped working correctly, meaning the system can no longer tell how hot the water is and has shut down 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: Flow sensor shorted or open circuit
What causes this fault?
This fault occurs when the boiler's control board loses communication with the temperature sensor on the main water pipe. The most common reason is that the internal sensor has suffered an electrical failure or the wiring connecting it has corroded over time. Since the boiler cannot safely monitor how hot the water is getting, it shuts down to prevent the system from overheating.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
Find a Gas Safe engineer
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