BoilerFaultCodesTechnical description
The temperature measured by the flue gas sensor is too high and is open
What causes this fault?
This fault occurs when the internal safety sensors detect that the exhaust gases are becoming hot enough to potentially damage the boiler's components. The most common reason is a buildup of debris or combustion by-products inside the heat exchanger, which prevents heat from being transferred to your radiators and instead pushes it out through the flue. It can also be triggered by a physical failure or loose connection within the temperature sensor itself.
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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