I have had a maintenance agreement with 1-hour for the last year and a half. It has more than paid for itself. And then 3 days before Christmas, the furnace went out. 1 hour was out in a flash.
One of the great things about these folks is that the review the options with you carefully. They take the time to have you completely understand what the problem is, and what options you may have.
We decided to put a new furnace in. Turns out there was an issue with the new unit installed. 1 Hour was out immediately. They diagnosed the problem with direct interaction with the manufacturer and we had a nice warm home just in time for the freeze that came.
These guys are always very neat and tidy. They put booties over their shoes so that they don't track in dirt.
I highly recommend One-Hour Heating and Air