what's this valve?

wirsbozo

Hi! I have a multi-zone hydronic heating system, and the valve in the below picture (round honeywell) is weeping. The tech I had over working on other parts of the system did not know where/what to replace it with or even whether it was needed. There are other electronically operated valves in the system vice this one, which is apparently thermostatic/manual.

Sending an up close shot of the valve and a wider shot of the system. Excuse my ignorance of the system itself, only been living here a few months and am trying to learn as much as I can about it and get it all squared away. Thanks!

hot_rod

looks like a Honeywell flow check FC 200 SB They prevent "ghost" flow in the piping when the circulator pumps are n ot running.
Do you have any zones over-heating? that is an indication of a stuck or clogged flow check.

wirsbozo

Thanks very much for helping ID the valve and its function!! I haven't used any of the zones for any length of time due to trying to sort out various other issues, but I haven't yet observed any overheating.

hot_rod

Looks like an old Sparco/ Honeywell power track zone valve to the left. that may have been added to prevent some ghost flow in that zone, or to make up for a failed flow check. In some cases you need a check on both supply and return as you can get reverse flow up the return side. that is when plumbers add that additional valve.

The system could use some freshening up, for sure. If everything works as expected, ride it out