I had always had problems with my french doors then one day i couldnt open them at all, Simon came out and got the doors open (god knows how!) and replaced something called a gearbox. A few months later i noticed the doors were a little stiff so called Simon, he came out first thing the next morning and showed me that the doors had dropped , he adjusted the doors and they work better and smoother now than they ever have! And i didnt get charged a penny for the door adjustment, it was included in the service. I would strongly recommend St Locks and Simon to anyone who has trouble with their UPVC doors.