BoilerFaultCodesWhat the manual says
Manufacturer manualFlow Temp Overheat Lockout
What causes this fault?
This fault occurs when the internal sensors detect that the water is heating up too quickly or has reached a dangerously high temperature. The most common reason is that the water cannot move through the boiler properly, which is often caused by a failed pump, a blockage of sludge in the system, or air trapped within the unit.
This issue is more frequent during the first cold spell of autumn, when the heating is turned on after a long period of inactivity and the pump has seized up.
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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