BoilerFaultCodesWhat the manual says
Manufacturer manualLow water pressure (sealed system), Overheat cut off device tripped or thermostat, overheat cut off device faulty.
What causes this fault?
This fault occurs when the water inside the boiler exceeds a safe operating temperature or if there isn't enough water circulating to carry heat away. The most common reasons are a build-up of sludge blocking the heat exchanger, a failing pump, or a simple loss of pressure in the central heating pipes.
This issue often appears when the heating is first turned on in autumn, as pumps can seize after being inactive during the summer months.
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 Neon 2 NOT lit: no call-out fees, no surprise bills.
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