Can I have two thermostats connected to the same zone on my Taco Controller?
I have two Taco Controllers with a total of 9 Hot Water zones. One of my Hot Water zones is for the Entrance Hall, Living Room and Dining Room. The thermostat is in the dining room and set to 70 during the day and I’m trying to establish a minimum temperature for the Entrance Hall area.
On cold day’s the entrance hall will be 10-12 degrees colder than the Living and Dining Room. I wanted to know if I could add a second thermostat that is wired directly to same Taco zone. I would set this second Thermostat to call for heat and stop calling for heat a a temperature below 70 degrees. For example, the Entrance Hall Thermostat might call for heat at 64 Degrees and stopped calling for heat at 68 degrees. The Dining Room Thermostat would call for heat when the dining room was below 70 degrees.
I do realize that when either thermostat is calling for heat, all areas in that zone would be heated.
Best Answer
As others have commented: The answer is yes. The area will be heated until both thermostats turn off, and one area might be overheated.
A cleaner way to do this would be to buy a digital thermostat with a remote sensor (e.g. an ecobee) and have a schedule that either switches the driving input between the base and the remote sensor or averages them. You can use heat correction factors to instruct the thermostat to do something like '70 in the living room or 65 in the entryway'.
Longer term, a fan, an extra zone, an extra space heater or a new loop may be necessary to get a more balanced temperature.