“I swapped out a Taco SR-503 with this EXP model because it offers a C terminal for each of my smart thermostats. Really easy to wire, and works flawlessly.”
“I purchased this unit and it arrived in less than 24 hrs. It saved me time and a lot of aggravation. It is so simple to wire your connection and the price was the best, no matter where I looked.”
“I have a radiant heat system that had some water leak from the backflow preventer and shorted out my current SR504 module from Taco. This was installed circa 2003 and had big "ice cube" relays. It also looks like the picture (as of this writing). The new one (this one”
“I used this relay switch with the thermostat that I also ordered to control the circulation pump for my in-floor heating system that I constructed. Both had good instructions for a do-it-yourself person like me. Worked great right from the start when I first put it into operation 2 weeks ago now. Both great products.”
