Circuit setter problem

[jackofalltrades]

I just started working at a small college and have questions. The first of many I will ask is that we have a few hydronic circuit setters that do not allow water to flow (heat). Most of them are all the way open, and when you close them partially and then re-open, they work fine.... for a couple weeks anyway. Could this be caused by dirt or other particals in the system, or something in the valve?

[twcpipes]

Yes. If they will let you take the time to pull one you can check the condition of the piping and water at that point of the system. Or ask the chief engineer, if you have one, what he knows about the water system and if it has ever had treatment put in and kept up or checked for that matter. It could be full of rust and just plain old "gunk".
A lot of times, what happens is, a leak will occur and it is fixed and then just plain water is put back to fill the system. Everytime the system is opened, the water treatment must be checked prior to refilling. Hope this helps.
Good luck.