Precision Matters: Installing the AV Heritage Plus Lock Correctly

Written By Richard Tavini

The AV Heritage Plus lock is a slam-shut locking system designed for performance and reliability. However, to function as intended, this lock requires precise installation to very specific tolerances.

Any deviation in the gaps between the door and frame can result in improper operation — including failure to latch, excessive wear, or reduced security. The following guide outlines the required installation specifications and tolerances.

Key Installation Requirements

Head Gap (Top of Door)

  • Required gap: 4mm

  • Tolerance: ±0.5mm

  • Requirement: The gap must be parallel across the entire width of the door.

Why it matters:
Incorrect or uneven head gaps can interfere with the vertical alignment of the locking mechanism, causing the door to bind or fail to close properly.

Lock Side Gap (Latch Side)

  • Required gap: 4mm

  • Tolerance: ±0.5mm

  • Requirement: The gap must be parallel along the entire height of the door.

Why it matters:
The lock must align precisely with the keep. An uneven or incorrect lock-side gap will result in poor engagement or jamming.

Viewing Gap (Hinge Side)

  • Requirement: The gap must be parallel along the entire height of the door.

Why it matters:
While there is no fixed dimension provided, the viewing gap must remain consistent to ensure even door movement and proper weight distribution across the hinges.

Installation Tips for Best Results

  • Use gap gauges or calibrated spacers during door fitting.

  • Measure both top and bottom (or full height) to confirm parallel alignment.

  • Ensure the door frame is square, plumb, and not twisted — even minor warping can impact lock performance.

  • Inspect lock operation after final fit to confirm the slam shut function works smoothly, without force.

Final Notes

The AV Heritage Plus and other AV locks rely on tight tolerances to deliver the performance they’re designed for. All gaps — particularly the head and lock side — must be exact and consistent.

Installing the door to spec from the outset ensures long-term reliability, reduces callbacks, and maintains warranty compliance.

Always measure carefully. Always verify alignment before final fixings. 

Richard Tavini
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