BoilerFaultCodesWhat the manual says
Manufacturer manualFlow sensor above 95 °C
What causes this fault?
This fault occurs when the water leaving the boiler exceeds a safe temperature limit, causing the system to shut down to protect itself. The most common reason is a lack of water circulation, often caused by a failing pump or a blockage within the main heat exchanger that prevents heat from being carried away quickly enough.
This issue is more common during the first cold spell of autumn, when pumps that have sat idle all summer can seize up or struggle to move heavy sludge that has settled in the radiators.
Engineer required
This is a emergency 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 b 18: no call-out fees, no surprise bills.
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