This is an older one notice that it has two screws on the same side. (it has 2 others on the bottom) this is the older style. To replace the head on this you will have to turn the water off and drain this pipe. But you will only have to do this once because the new zone valve parts mount to this body. So you don't have to look for special parts for an older Honeywell zone valve, just buy a new 3/4" sweat zone valve. And I will show you how to make it work.