DETAILED ANSWER · UPVC DOORS AND MECHANISMS
What is a multipoint locking mechanism?
Understand common symptoms across cylinders, handles and multipoint locks.
A multipoint lock uses a central mechanism and connected locking points along a door edge. Lifting the handle commonly moves the points into keeps in the frame; the key or thumbturn then secures the mechanism, depending on the design. The exact layout varies by manufacturer and model.
A photo of the door edge can help identify the system. Multipoint systems vary: some use hooks, rollers, bolts or combinations, and the key cylinder may lock the central mechanism after the handle raises the points. Avoid assuming all points are engaged because the handle moved.
If the door does not close or lock normally, do not rely on it as the only secure entrance. A photo of the edge strip and the manufacturer's markings can help identify the system.