In order for your doors to open and run smoothly they need to be correctly fitted to ensure they are not too tight in the runners, that they run level and finally that they are lubricated.Using the spanner supplied with your shower follow the instructing in the manual to align the door heights and so they open and close without binding. Once the doors are opening and closing smoothly, you may wish to apply some silicone lubricant spray. Due to the door wheels (Cams) coming into constant contact with water and detergents, the wheels may become awkward to move, by regular cleaning and lubrication of the wheels, you can ensure they provide a long service life.