BoilerFaultCodesTechnical description
Primary (flow) sensor fault
What causes this fault?
This fault occurs when the boiler's control board loses communication with the sensor that monitors the heat of the water leaving the unit. The most common reason is that the sensor has physically failed or developed a loose connection, meaning the boiler can no longer safely verify the water temperature. To prevent overheating, the system automatically shuts down until the faulty component is replaced.
Engineer required
This is a high severity fault. Stop using the boiler and call a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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