Lockout button lit High

Grant Lockout button lit Fault Code

Also written as LOCKOUTBUTTONLIT — same fault.

The Grant Lockout button lit fault code means: your boiler has stopped working to protect itself and needs a simple reset, but it may require professional attention if it fails to restart.. It appears on 6 Grant 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: Burner Lockout. Press ‘Lockout’ button to reset burner. If burner does not fire – refer to Section 12.4 Burner Fault Finding.
Typical repair cost £120-250 (including labour)

Engineer required

This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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Grant models that show the Lockout button lit fault code

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

Source

Grant Lockout button 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 7 July 2026