I was contacted by a concerned father regarding his daughter's composite door. The door had become difficult to use, the handles would lift but none of the locking points moved, and the door was catching the frame whenever it was closed. He was worried the door would need replacing and feared it was going to cost a small fortune.
After inspecting the door, it quickly became clear that the door itself wasn't the problem. The main fault was a failed gearbox within the multipoint locking mechanism. Fortunately, this meant the existing door could be repaired rather than replaced. Can a Faulty Gearbox Be Repaired? explains why a failed gearbox doesn't usually mean a new door is needed.
Diagnosing the Fault
The symptoms all pointed towards a gearbox failure.
Although the handles lifted, the gearbox was no longer transferring movement to the locking points, preventing the hooks and bolts from engaging correctly.
This is a common failure on uPVC and composite doors and, in many cases, can be repaired by replacing the gearbox rather than the complete locking mechanism.
More Than One Problem
While carrying out the repair, I also checked the rest of the locking system to make sure there weren't any other issues that could shorten the life of the new gearbox.
As part of the repair I:
- Replaced the failed gearbox.
- Supplied and fitted a new lock cylinder with five new keys.
- Fitted a missing keep on the frame that had been affecting the operation of the locking mechanism.
A professional repair should always address every fault rather than simply replacing the obvious failed component.
Door Realignment
The door had also moved out of alignment over time.
Using the hinges, I carefully realigned the door so it sat correctly within the frame. This ensured the locking points lined up properly with the keeps and removed unnecessary strain from the locking mechanism. Door Realignment Gets Your Door Working Like New Again explains why correct alignment is essential for long-term reliability.
Seized Locking Points
During the final testing, I noticed the lock was still much tighter than it should have been.
Further inspection showed that several of the locking points had become seized through lack of use and the ongoing strain caused by the door being out of alignment.
These were carefully cleaned, freed off and adjusted until they operated smoothly again.
By resolving every issue before completing the repair, the locking system could operate as it was designed rather than continuing to work under unnecessary pressure.
Fully Restored
Once everything had been repaired and adjusted:
- The handles lifted smoothly.
- Every locking point engaged correctly.
- The key turned effortlessly.
- The door sealed tightly against the frame.
- The lock operated exactly as it should.
The customer was delighted to discover the door could be repaired rather than replaced. What he thought might require an expensive new composite door was resolved by repairing and servicing the existing locking system. He was so pleased with the result that he kindly left a 5-star review.
Repair Before You Replace
This repair is another example of why a faulty composite door doesn't automatically need replacing. A failed gearbox, poor alignment, missing hardware or seized locking points can often be repaired at a fraction of the cost of a new door. You Don't Need a New Door – We Can Repair It explains why repairing the original door is usually the most cost-effective option, while uPVC Door Realignment and Lock Adjustment shows how proper alignment helps protect the locking mechanism and prevent future failures.
