“This purchase was a spare. It seems the only time the heat goes out is on the weekend. Replaced one a few weeks before this purchase, so I decided to get a spare as I have a 2 zone system.”
“The power head on a Taco hot water heating zone valve is easy to change, but there are a few very important things to keep in mind. (1) Write down the colors of the wires and what terminal each colored wire goes to before disconnecting them. Or take a picture of them with your smart phone. (2) This is VERY IMPORTANT. Turn the power to your furnace off and leave it off for two or more minutes before removing the power head from the valve and before disconnecting any wires. First, if you accidently short the wires together you may destroy your 24 volt transformer that powers the valve heads and your thermostats. You can be sure that the power head does not have power by disconnecting the wire from the #1 terminal. Second, the power head works by heating a fluid inside the head and that pushes a pin down to open the valve. If the valve head is powered up when you remove it from the valve, the pin might shoot out the bottom of the power head with a lot of force and it may spray hot fluid out possibly causing a serious burn. This might be rare, but it is possible. Don't take a chance!”
