BoilerFaultCodesYour boiler is receiving electrical power and is in standby mode or waiting for a signal to heat up.
This is a minor fault. Keep an eye on it and mention it at your next annual boiler service. Reset the boiler and see if it clears.
Technical description: MAINS ON
What causes this fault?
This is not actually a fault, but a status indicator showing that your boiler has a healthy electrical supply. It means the appliance is sitting in standby mode and is simply waiting for a signal from your thermostat or programmer to start heating your home. If your heating isn't coming on while this light is showing, the issue is likely with your external controls rather than the boiler itself.
DIY fix possible
Check that your external room thermostat or programmer is turned up and calling for heatEnsure the boiler control knob is not set to the 'Off' positionWait a few minutes to see if the boiler begins its ignition sequence automatically
Find a Gas Safe engineer
Search the official register for a qualified engineer in your area.
Gas Safe Register →Protect yourself from future repair bills
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