Thermal installed a sliding glass door for us. The door became very difficult to shut and the company had come to adjust it several times. Over the course of the next couple years, the door required increasing effort to shut. The frame eventually separated due to the repeated slamming that was required to shut it. We paid for a new frame, which Thermal installed. Now, only a year later, the door is becoming very difficult to close again. Thermal is now refusing to correct the problem without us paying a $90 service call fee. The company has been very difficult to deal with. Whether improperly installed, or simply inferior quality, the door has been very problematic, and Thermal won't work with us.