How much does it cost to fix Grant error code Lock-out reset button is lit?

Typical repair cost for the Grant Lock-out reset button is lit fault is £120-250 including labour.

Lock-out reset button is lit High

Grant Lock-out reset button is lit Fault Code

Q: What does the Grant Lock-out reset button is lit fault code mean?

Your boiler has detected a problem with the combustion process and has safely shut itself down to prevent any hazards.

Also written as LOCKOUTRESETBUTTONISLIT — same fault.

The Grant Lock-out reset button is lit fault code means: your boiler has detected a problem with the combustion process and has safely shut itself down to prevent any hazards.. It appears on 1 Grant model in our database.

Technical description: If there is a burner malfunction, a built-in safety circuit switches the burner off and the Lock-out reset button will light.

Typical repair cost £120-250 (including labour)

DIY fix possible

Check your external fuel supply level (if oil) to ensure the system is not starved of fuel.Wait five minutes to allow the system to clear, then firmly press the illuminated reset button once.If the boiler fails to restart after one attempt, do not repeatedly press the button as this can cause flooding of the combustion chamber.

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Grant models that show the Lock-out reset button is lit fault code

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

Vortex Combi 70 Repair: £120-250

Source

Grant Lock-out reset button is lit fault code information on this page is sourced and cross-checked against the official Grant service / installation manuals for each affected model.

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