BoilerFaultCodes.com
153 High Lockout

Your boiler has been manually reset too many times and has temporarily locked itself to prevent further issues.

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: Forced reset unit unlocked

What causes this fault?

This fault occurs when the reset button has been pressed more than five times within a one-hour period. It is a safety feature designed to prevent you from repeatedly trying to start a boiler that has a persistent internal problem. The boiler essentially stops responding to resets to protect its components from further damage.

Typical repair cost £0-120 (including labour)

DIY fix possible

Switch the boiler electrical supply off at the spur switchWait for at least 30 secondsSwitch the power back on to allow the system to clear the lockout

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