I have to nest thermostats and they work great though they required quite a bit of programming. I also connected my water heater/re circulation pump to be off at night and when nobody is home and connected my gas fireplace. A power or vibration sensor for the washing machine is very useful, too as well as a connected doorbell (I just used a vibration sensor). I also connected my hard wired smoke/CO alarms to turn on all lights, unlock doors and turn off HVAC and fireplace in case of an alarm.