These UPVC bi-fold doors had started to become clunky whenever they were being used. What started as simply an annoying flaw after their initial installation had meant this Chertsey homeowner had to put up with almost inoperable bifold doors for months. When a bifold doors becomes misaligned, it can result in drafts in a home. The constant force that is needed to open and close the doors could lead to more costly, more permanent damage too. 
Thankfully, we were called in time and carried out a quick door realignment service. Had the issue of been left for much longer, the runner could have broken which would have cost a lot more to put right.