"Cram" wrote in message
oups.com...
On my home forced hot water heating system, the upstairs zone will not
stop circulating heat.

I want to rule out a few factors. One of them is trying to figure out
this valve:

http://www.marcsawyer.com/pics/combovalve.jpg

I've been searching the web to simply find the name of the valve so I
can determine how that tab next to the purge functions; ie.
closed/open/partial flow...

Any takers? C'mon! it's a picture game!

Marc


I would guess the small valve is for controlling flow amount, The larger
valve might be for bleeding air out of the system if this valve is at a high
point of the system? If its down low it might just be to drain the system.
Could it be to isolate the pump for replacement or service ?