It's been a day wife woke me this morning saying thermostat was bad went and got a new one. It was woking so I wasn't worried about it went riding and then moved hospital bed and lift chair to my grandfather in law's with my in-laws that was an event. Got home went to install new thermostat it is a smart thermostat neededa 5th c wire which I didn't have in the old one. Thought it wouldn't work so wife ran to Lowes to get a regular thermostat. Meanwhile house is getting cold I google find that I can hook a c wire in furnace panel if I have an extra wire which I did. So hooked up the c wire got smart thermostat working but heater won't kick on throwing fault code. Reset it thought it was working then nope fault code found condensate line plugged and had water backed up into the fan drained that all out blew everything out. Finally after a few times blowing it out and checking I think I got it working it ran twice now got the hose back up to temp at least. Called a emergency tech at one point I was lost they couldn't come till tomorrow at the earliest and that I was "on the right track" with blowing it out call him tomorrow if I don't get it

Oh and the "smart" thermostat isn't so smart cause I need a dual band router to connect to wifi it won't connect to 5g router. so I still have to set in manually though the display pita
