The first time I turned on the heat this year... it didnt work. the furnance is about 30 years old, so i worried that I was going to pay thousands. I called Bolls based on Angies List reports - they were able to schedule an appointment for the next day. The technician who came out quickly identified that it was a control board. He had to return to the the office to get the part he needed but in all diagnosis and repair were done in less than three hours.