Zone Valve Replacement Head for 560 Series

The 560 series zone valve replacement head is now identical to the 570 series and preformed as advertised.

I use this to control drain back water in a DIY hot water solar system

In my setup, this power head is on a 3-way zone valve that controls flow to a hot water storage tank. I installed it, turned the system back on and as expected, the boiler came on to satisfy the thermostat in the tank. All is well - or is it? Because of where the boiler is located and becasue it's so quiet, I don't normally know whether it's running or not (not like the HydroTherm pulse heater that preceded it). Yesterday, I happened to be checking out something in very close proximity to the heater and heard something. When I finally traced the barely audible sound, I found that the circulator was running even though I knew all of the thermostats were satisfied. I was not able to investigate further until tonight. In very short order, I had determined that the #2 and # 3 terminals were "closed". Upon disassembling the head I immediately noticed that a metal tab that is supposed to hold the contact switch open when the head is not receiving power was in the totally incorrect position. It looked like it had been installed that way during the manufacturing process because it never could have rotated into the position I found it in. [In the attached photo, the tab can be seen at the approx. 1-2 o'clock position when it should be at the twelve o'clock position.] As I was able to get it back into its proper position and reassemble the head, it is now operating as intended. Since I installed it for the first time two weeks ago, apparently the boiler's been running non stop other than cycling off on high limit for all that time. Hopefully this was just a one in hundreds of thousands situation but you never know. And again, to be perfectly clear, what I found is something that would have happened in the manufacturing process at Taco and thus really has no adversse bearing on PexSupply.