I attended a job today where the customer was concerned about a visible gap around her uPVC door. She had noticed daylight showing through the top and bottom corner of the door and was also finding that the key had become stiff and sticky when locking it.

At first glance, many homeowners assume this means the lock is failing or that the door needs replacing. In reality, the cause was much simpler.

After inspecting the door, it was immediately clear that it had dropped out of alignment. The bottom of the door had pulled too far back, leaving it sitting unevenly within the frame. This created the visible gaps, prevented the weather seal from making proper contact and placed additional strain on the locking mechanism every time the key was turned.

The first step was to correctly realign the door and adjust the hinges so it sat squarely within the frame again. As soon as the alignment was restored, the daylight gaps disappeared and the door sealed properly once more.

I then investigated the stiff lock. Although the alignment had improved the operation, there was still some resistance when locking the door. A closer inspection showed that the centre keep had been positioned incorrectly, causing the locking mechanism to bind each time the key was turned.

To resolve this, I removed the keep, made a minor adjustment to the frame and repositioned the keep so the locking point engaged correctly without resistance.

Once everything had been adjusted and tested, the difference was immediate. The door closed smoothly, the key turned effortlessly and the locking mechanism operated exactly as it should.

The customer was delighted with the result. What looked like a serious problem that might have required a new door was actually resolved through careful door realignment and a small adjustment to the locking hardware. She was so pleased with the repair that she kindly left a 5-star review.

This job is a good reminder that stiff locks, visible gaps and difficult locking are often symptoms of poor door alignment rather than failed locks. Identifying and correcting the underlying cause not only restores smooth operation but also helps prevent unnecessary wear on the gearbox and multipoint locking mechanism, extending the life of the door and avoiding the cost of a replacement.