BoilerFaultCodesWhat the manual says
Manufacturer manualIf not lit this indicates either timer or programmer is not calling for hot water / switch is not set to constant
What causes this fault?
This occurs when there is a break in communication between your heating controls and the boiler. The most common reason is that your room thermostat or timer hasn't been set high enough to trigger a heat request, but it can also be caused by flat batteries in a wireless controller or a faulty receiver box failing to pass the signal through.
This issue is frequently noticed during the first cold spell of autumn when homeowners try to switch their heating on for the first time after the summer break.
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 Demand: no call-out fees, no surprise bills.
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