A lot of what we do every week is unlock uPVC and composite doors where the locking system has failed, leaving the door unable to be opened. These doors have a full length locking system and the part in the middle (situated behind where the handles are) is the gearbox. This is the complex part of the locking system that enables the hook bolts or rollers to move up and down or in and out, locking and unlocking the door. This door lock failure happened in Kingsway (This housing estate only seems to have composite doors on the front of all the properties – so they all have a locking system where you have to lift the handle to be able to lock the door).
It is common for this part to fail. Often this is due to the door being incorrectly aligned in the frame. If the door is difficult to close and or to lock / unlock then door alignment may well have something to do with it. When you have to exert extra force on the handles to lock or unlock the door, you are putting that extra force through the gearbox part of the locking system. It can’t cope with too much of that and fails.
This is when we’re asked to come and sort the problem out. If we were called when the door was getting difficult to lock, we could have adjusted the door and saved the cost of replacing the gearbox.
This was a simple gearbox replacement. A Yale type gearbox. Most of this estate has a different type of gearbox, but on this property it had a 45mm Yale locking system.