BoilerFaultCodes.com
Green LED Off, Yellow LED Off, Red LED On High Lockout

Your boiler has encountered a system error and has shut down as a safety precaution.

Call an engineer soon

Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.

Technical description: Internal fault (Reset, see page 5)

What causes this fault?

This fault occurs when the boiler's internal computer, the Printed Circuit Board, detects a serious error within its own circuitry or fails to communicate with the ignition system. The most common reason is an electrical component failure or a worn-out ignition electrode that is no longer able to safely start the burner.

Typical repair cost £180-350 (including labour)

DIY fix possible

Locate the mode selector switch on the front of the boiler.Turn the switch to the 'OFF/RESET' position and wait for 10 seconds.Turn the switch back to either 'Hot Water Only' or 'Heating and Hot Water' and wait for the boiler to restart.

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