Was installed professionally. I have in floor heating. A number of set-up issues came up that I could not resolve. I called customer service and the issues were resolved. A couple of the issues relate to gaps/holes in the Honeywell instructions. A couple I am still working out may have to do with how slowly in floor heating increases temperature. I will come back and review again after I get the thermostat working. Short answer. It did not, in my case, simply work.