What the manual says
Manufacturer manualBurnermode:Heating
What causes this fault?
This is a normal status message indicating that your boiler is currently in 'Heating Mode' and the burner is successfully lit to provide warmth to your radiators. It appears when the internal thermostat calls for heat and the startup sequence has completed without any issues. Because this is a standard operating state rather than a failure, no repair is necessary.
This code is most frequently seen during the autumn and winter months when the central heating is programmed to be active for longer periods.
Engineer required
This fault requires 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 S.4: no call-out fees, no surprise bills.
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