BoilerFaultCodesWhat the manual says
Manufacturer manualActual temperature: Flow temperature at the flow temperature sensor.
What causes this fault?
This fault occurs when the water leaving the boiler exceeds its safe temperature limit, causing the system to shut down for safety. The most common reasons are a blockage in the pipework, a pump that has failed to circulate the water, or a buildup of debris inside the heat exchanger that restricts water flow.
This fault is more common when heating is first turned on after a long summer break, as internal pump components can seize during periods of inactivity.
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.
Avoid the next call-out bill
A cover plan would handle faults like 1-A5: no call-out fees, no surprise bills.
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