BoilerFaultCodesGrant Burner Lock-out Fault Code
Also written as BURNERLOCKOUT — same fault.
The Grant Burner Lock-out fault code means: your boiler has stopped working because it failed to light the flame safely, and it now needs a manual reset to try restarting.. It appears on 5 Grant models 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.
DIY fix possible
Check your oil tank is not empty and the fuel supply valve is open.Wait for the red light on the burner to illuminate, then press and hold the reset button for 3 seconds.If the boiler tries to start but stops again, do not force repeated resets.
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Grant models that show the Burner Lock-out fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Grant Burner Lock-out 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 31 August 2026