We built our house 30 years ago using electric baseboard heat. This is 240 volt electric heat. We would like to change the original thermostats (Mears M7) to progammable digital themostats. Those that we have looked at indicate two models; single pole and double pole. How would I determine which one I need to use. We are currently looking as Marley TH110SPP and TH110DPP models.
Thank you
WL