I replaced mine with a Sensi. 4 months with Nest, and it decided to confuse hot vs cold signals. Middle of August, it tried to “cool” my house at 3am, instead turning on the furnace, and just kept on going due to the temperature rising. For a week straight, I awoke to 90 degree temps in my house at 3:30 to 4am, and a nice heating bill. I had an hvac friend come over ad tell me in fact, yep, it’s sending signal to furnace, not ac. He checked the wiring, all good. He admitted he knew little of Nests, but said only an idiot would design a thermostat that could allow for a hot/cold signal switch without rewiring.