vibrating flow-check

gkirst

I have a vibrating flow check(1 1/4") with a Taco 007 circ feeding supply side appr. 10" belowflow-check. It's a pump-away feeding a small basement cast-iron loop about 60 ft total pipe, 30 ft baseboard. No air. The flow check is at the ceiling, on rt. angle to the circ. Extrol 30 with a purge spaced 20" from boiler riser and on a header with 4 more circs, all 007's, including a storage tank. This is the only zone with the problem. What's happening? Flow is great during purge so I don't think it's restricted. It actually changes frequency and modulation as it runs making it sound horrible upstairs.

Greg

Tim McElwain

Try putting on manual run

the system and then put back to automatic if it still acts up have it replaced.

Tony_23

flow

Did it just start this ?



Sounds like a flow issue. Either fluctuating or too fast.

Big Ed_4

Too Big

Your flow valve maybe too big, the weight inside not fully rising and chattering , Too big for the flow... may need to drop it down a size ... I am assuming you are not feeding a small 18K loop with a 1 1/4 supply pipe ?



Could also be too much flow and high restriction which would cause a hydronic noise ... Test .... Open the flow valve and see if the noise stops.. If it does drop the flow valve size down .... If still persists lets look at the pipe set up and circulators

haventseenenough

flow check

Is the check seated? A partially open valve will make noise. Easily rebuilt in place also.

Brad White

I agree with Big Ed

and would consider that first.



I had a similar zone situation where "penny wise and pound foolish", the 1.25" flow check was re-used for a relatively small zone which served two radiators with TRV's and a third without. (The third radiator was in effect the bypass).



In this case the circulator was replaced with a smaller one, in all fairness but keeping the angle flow check. The problem became worse when radiator TRV's began to close.



No amount of manual intervention short of "open" solved it and the sound did carry as it so often does.



Replacing the initial piping including the flow check and circulator to an IFC circulator solved it.



My $0.02

Brad

gkirst

Thanks fellas,from Greg

Just wanted to thank you guys for your advice. I pretty much knew the flo-check was getting changed, I just didn't understand why. I completely removed the flo-check and installed a Taco 007 IFC. End of problem. Still, I may never see this again, and would have loved to understand what happened. Oh, and I didn't mention that it made noise even during purge. When I took it apart after removing, I could not see any indication of movement. Any case, it's fixed and I appreciate your help.

Thanks again,

Greg