Replaced a carrier 3ton with Heil 2 1/2 ton 96% eff. Installed new Honeywell 9000 WiFi thermostat. The tstat loses power when burners turn off. Then cycles back on. The ac works fine w the tstat. Also heat was reaching 150 deg. And heat shutting down. Had a bad burning smell and even saw some smoke when opened the top door. Increased fan speed and installed a new return. Solved that. But tstat still losing power. Need help.
From an "answer" by the OP that should have been edited into the question:
had tech out. It’s wired correctly. No one seems to know what the issue is. Saying need to replace wire coming in from condenser. But what does that have to do with the furnace? Also. Just hapless again, unit giving code 4. Which was said that we needed a new return. So after putting a hole in y living room floor right above the heater (basement). Not only does it sound like I’m in an airport. The unit still throwing code and burners shut down, stat loses power,Fan still runs, then stat comes back on