Overview
A multi-point mechanism engages 3-7 locking points down the door edge in one handle lift. When one or more stops working, the door is dramatically less secure - insurance will often refuse claims where the mechanism was known-faulty.
Symptoms
- Handle lifts but you can hear only some of the hooks engage.
- One hook or bolt visibly doesn't extend.
- Handle feels lighter than usual - no spring resistance.
- Door pushes open even with the handle up.
Common causes
- Broken gearbox - one output has failed while others still work.
- Broken drive-bar link between the gearbox and the hook.
- Bent hook after forced closing.
- Snapped internal spring.
When to call a professional
- Any point that isn't engaging.
- The door is no longer PAS24 compliant without a working mechanism.
Prevention
- Lubricate the cylinder twice a year with a graphite or PTFE lock spray - never WD-40 or oil.
- Grease the hooks and rollers on the door edge every 6 months.
- Always lift the handle to engage the multi-point locks before turning the key - this takes load off the gearbox.
- Never force a stiff key - book a service call before the mechanism snaps.