Five months ago, we had a new installation of two heat pumps. During the recent cold snap, the thermostat registered "auxiliary heat." Mr. Cook visited, problem-solved, and charged nothing. A day later, we discovered the problem was the old thermostat. He was there immediately with a new one and promised that if this wasn't the solution, he would refund the equipment and the service call. How's that for customer service?! Thanks, Precision!