Had an issue with my furnace fan not shutting off, the heating worked fine. A tech came to the house the day before Thanksgiving, said my furnace is not the problem, and the issue is with my thermostat and that it should be replaced. Also said my thermostat (Nest) was not compatible with my Lennox furnace. I have had this Nest product working fine for over 4 years now . . . not sure why compatibility could be the problem. After the tech left, the furnace stopped working altogether (no heat). I called Econo Air, spoke a lady who said she would contact a tech person, and she would call me back within an hour. She never called. The next day on Thanksgiving, with family coming over to a house without heat (was like an icebox). Wonderful, not to mention a really cold night's sleep. Called another company to come out the next day, only to find that the previous tech left the furnace cover ajar which disables the cover switch, rendering the unit inoperable. He put the cover on correctly, and everything worked just fine. Made an adjustment somewhere with the wiring, and now all is perfect. Said my thermostat works fine, no need to replace. To this day (a week later), still no call from Econo Air as promised earlier. NOTE: I asked the tech from Econo Air what it would cost to replace the furnace altogether. He said around $9,000. I have since gotten quotes from other companies between $3,800 to $4,200. I will have no further business with Econo Air.