Lockout light illuminated High

Potterton Lockout light illuminated Fault Code

Also written as LOCKOUTLIGHTILLUMINATED — same fault.

The Potterton Lockout light illuminated fault code means: your boiler has stopped working for safety reasons because it either cannot light the flame or the system has become too hot.. It appears on 2 Potterton models in our database.

Call an engineer soon

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

Technical description: Loss of gas supply, flame failure, or over-heating of the central heating water will cause the appliance to shut down or Lockout.
Typical repair cost £100-£350 (including labour)

DIY fix possible

Check that your gas pre-payment meter (if you have one) has credit.Ensure the gas stopcock is fully turned on.Press the reset button once to try and restart the boiler.If the boiler has overheated, let it cool for 20 minutes before resetting.

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Potterton models that show the Lockout light illuminated fault code

Click a model for the full fault code list and model-specific repair notes.

Source

Potterton Lockout light illuminated fault code information on this page is sourced and cross-checked against the official Potterton service / installation manuals for each affected model.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 27 April 2026