Help w/ converting old hater water radiator system thermostat to smart thermostat

[Jeff Davis]

Hey all - 

Wondering if anyone has experience switching out an old Honeywell thermostat that is used for a hot water heater system to a smart thermostat (we bought the Amazon smart thermostat). - see attached photos

It's for our new airbnb listing. We are in the process of rehabbing an old 2-story multifamily building and the thermostat for the entire building is on the 1st floor which is where the Aribnb will be. We would like to be able to control this remotely thus we need to switch the thermostat. 

Have been unsuccessfully in finding someone that has experience doing this at a reasonable price as this is our first rehab. 

Any help would be greatly appreciated!

[Ryan Pearson]

Hi Jeff,  I believe your going to need a line voltage thermostat.  The Amazon smart thermostat that you have pictured is only compatable with low voltage HVAC 24V systems.  I was just in the same situation looking for a smart thermostat for a baseboard heater and two wall heaters (all 110V/220V line voltage) for a short term rental in Mammoth Lakes.  My research landed me on the MYSA thermostats.  I've been using them now for about 6 months and they work great. Super easy to use and very reliable.  Hope this helps.

Ryan

[Vesna Marcina]

Do you know if the Honeywell Thermostat is low voltage or line voltage? Is the water heater 110V or 220V? That determines your options and how challenging a project it is. If the voltage doesn't match up on the Honeywell and the Amazon thermostats, then the project is much more challenging. 

I wanted to add a smart thermostat to our baseboard heaters, but it ended up being a much bigger job than I wanted to take on at the time. Maybe after we're done remodeling, I will do it. This is what I learned:

--Purchase a line voltage thermostat as Ryan Pearson suggested if that is what is powering the Honeywell. OR

--Purchase a low-voltage transformer to connect to the smart thermostat. This option might not be particularly attractive depending on the placement of the transformer. 

In any case, I found diy.stackexchange.com very helpful. Lots of trade folks there willing to share their knowledge and advice. Here is my question and an illuminating answer that I got there: 
https://diy.stackexchange.com/...