I think you’re right about the recall, my electric company came out and installed this one 10 years ago but looking at my old thermostat there are no instructions.

but why is the current one working without a c wire?

did i not include a picture of that?

thank you! the one thing i would like the mention is that my current thermostat functions fine besides batteries dying fast and it not responding to the app

i thought so too but they did mention they only work with heat towards the end of the conversation.

is that bad? i dont know much about electrical work and im trying everything to get it working correctly. I called an hvac company and they told me to try an electrician. Ive trued every answer I’ve gotten and nothing has worked. My next thing to try that was suggested is using the blue as the c wire and jumping the rh and rc.

Thats what I originally thought but this is now my second Sensi ST55, both people on here and the Sensi said it would work with my system. First one I couldn’t get any heat and there was a loud buzz. The second one the heat just wouldn’t turn off. It was set to 68 and it got all the way up to 80 degrees. I have tried 3 different brands and 4 different thermostats (given the first one required a c wire) and I cant get it work like it is with my current thermostat.

I even had Sensi on the phone to go through the programming with the second one and they said it was set up correctly. The ONLY reason I am changing thermostats is because the current one’s app is a little wonky so it doesn’t stay true to changes made on the app and it goes through batteries like crazy all of a sudden

that should work even though my old thermostat that I had for 10 years used this exact wiring? both are smart thermostats that dont require a c wire

the new one I bought also uses batteries and does not require a c wire

Yeah we definitely want to change to a newer thermostat. I took the wires in and out multiples times, made sure they all the way in and tightly fastened down. It still just kept running the heat.

We change the batteries in the old one once a week and often it doesnt follow the schedule/respond to the app.

I will try the different wiring and see what happens. Thank you

I have very little to no knowledge about this so I didnt want to start changing wires around. I talked to an electrician over the phone briefly and sent him pictures and I was told all my wiring is correct. What I dont understand is how my old thermostat works but none of the three or four other brands that all say are compatible with my system dont work

right now the old thermostat is back on and working fine. When i first got the sensi st55 it didnt work at all and I never had heat working, when I got the new st55 blew hot air but would not stop when it reached set temp. My house got to 80 degrees, after messing around with all the settings to make sure I had it right for my type of heat and a/c and nothing changing I put my old thermostat back on