When my furnace stopped heating at 10pm I figured I was in for a very cold night. A friend referred me to Diamond and not only did they show up within 40 minutes they did not charge after hours fees. The technician did a fabulous job of fixing the problem quickly while explaining things to me so I would be prepared in the future if the problem repeated. I would reccommend this company to anyone needing their furnace serviced. They are economical, honest, and prompt.