BoilerFaultCodesWhat the manual says
Manufacturer manualFlow temperature overheat or no water flow
What causes this fault?
This fault occurs when the water inside your boiler reaches a temperature that is too high for safe operation. It is usually caused by a blockage in the pipework or a mechanical failure in the pump, which prevents water from moving away from the heat source quickly enough. In some cases, a buildup of debris or sludge in the system can restrict flow and trigger this safety shutdown.
This fault is more common in autumn when heating is turned back on after the summer, as internal pump parts can seize from lack of use.
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 L1: no call-out fees, no surprise bills.
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