BoilerFaultCodesWhat the manual says
Manufacturer manualMax. flow temperature
What causes this fault?
This fault occurs when the water inside your boiler cannot circulate fast enough to carry heat away from the burner, causing the internal temperature to spike instantly. The most common reasons are a failing pump that isn't pushing the water round, or a blockage caused by sludge and debris restricting the flow within the system.
This issue often surfaces during the first cold spell of autumn when the heating is turned back on after sitting idle all summer, which can cause internal pump parts to seize.
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 2.b: no call-out fees, no surprise bills.
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