Horrible! I'll set it at 72 like past winters for 30 yrs in my house & it's cold! Everyone says my house is very cold at 72. I'll put the temp setting on my phone from 74 to 70 at night & let the screen closed out. It worked fine for 2 yrs. Then I'd wake up sweating, open the app & the temp bounced back up to 74. I did everything exactly the same for 2 yrs. The wall therm showed 74. I reg update it. I haven't called tech support bcz when I called to set- up the guy was absolutely nasty rude!!