"Hydronic Heating System - Zone Thermostat"

By Ron Stultz

14 February 2009

Soon or later you are going to want to swap out your old thermostat(s) for newer, perhaps programmable, units and there are a wide variety of thermostats on the market to choose from and doing a thermostat swap is certainly not beyond the skill set of most homeowners BUT......

If you have Taco zone control valves you can not use just any old thermostat, as I found out. Taco zone control valves take almost a full ampere of current to activate and many thermostats can not provide, sink, that kind of current. What you will have to have is a thermostat that specifically works with zone control valves, i.e. has a small relay inside which actually handles Taco valve current. Problem is many thermostats at local building supply stores don't specifically call out that they work with zone control valves or not

So, if you want to upgrade your thermostat, just make sure it works with zone control valves.