Hello I just replaced my old White-Rodgers thermostat because it just wasn't working consistently (sometimes it would turn on the furnace, but mostly it wouldn't). I swapped it with a White-Rodgers Sensi thermostat.
Once I replaced the thermostat, the furnace turned immediately upon adjusting the thermostat to do so. (I'm thinking job well done right now)
Once the home reached it's target temperature, I felt cold air blowing. The furnace no longer blows hot air. Something happened while the furnace was running or about the time it got to it's stated temp that it just quite blowing hot air. Now it will not blow warm at all. Any ideas where to start? I'm going to replace the filter today and see if the Pilot is still lit, but I've not gone up in the attic yet.
The furnace is one without a pilot, it has an auto-ignition if that matters.