Opie's One Hour Heating and Air Conditioning came out a couple of times to check my air conditioning unit. The unit would not shut off. It had gotten down to 64 degrees at night and the air conditioner was set at 72. The technician checked out everything and he was able to get it to work. Well after he left again it would not work. The same technician came out the following day and replaced the thermostat and it has been working since. I have used them in the past and I would use them again for their knowledge and the overall cordiality and professionalism.