I inherited my home from my parents. They had their furnace installed and maintained by Crossville Heating and Cooling for several years. So when we moved in, we had an additional unit installed upstairs.
The front desk personnel is always very friendly. Appointments are readily available.
The only negative thing I have to say is I wish they still offered four maintenance plans -- it's all or nothing. It was also a lot easier to make monthly payments. They wouldn't even consider two payments. We looked elsewhere, but longevity won out this year.