B&G Flo Control Bypassing

Doug Burk

I am looking for some information on B&G model SA1 Flo Controls.
I have a customer who has an old American Standard boiler with a hot water coil and the old flo control was bypassing.

Eariler this week a new B&G flo control was installed and the situation is still the same , another tech from our company went and installed a new insert into the valve body
and checked the seat he said he found some solder inside .
Yesterday I went back to the customers house and installed whole new valve and the problem is still occuring.
I know that high temps can cause this to happen, after finishing the install of the new valve yesterday I checked the temp of the supply line going into the bottom of the valve and got a reading of 180 degrees which is normal.
So if anyone can help me figure out what I am missing I would appreciate it.

Rich P.

So its not boiling,

How about during large hot water draw, bath, is hi-limit work then? No chance of t-stat calling?
This can be tough, I have changed entire valve before, I never use swetcheks because of that. I'm not sure if its an IPS valve you have.
Good Luck

Doug Burk

Yes it is an ips valve , at this point system is only running for hot water- customer left tstat off to see if it still by passes.
have had problems in the past with flo checks bypassing but normally replacement of the valve solves the problem.
also something doesn't seem rite i could see maybe one valve having a problem out of the box but two valves and an insert all being bad?

Keith_8

Flow issues

Doug,

I never had much success with 3/4" IPS flow checks. Even if we had a 3/4 loop we installed a 1" flow check with 1 x 3/4 bushings. The disc weighs a little more on the 1".

Is it safe to assume that the flow check is on the supply and the flow problem is from the supply to return of the loop? I have seen flow checks on the supply and the ghost flow was happening in reverse. The hot water was backing up out of the return.

Is there a leak somewhere that you can't detect? That would cause water to leave the boiler.

Has another zone/pump been added? Has anything changed in the system?

If everything checks out maybe adding a zone valve is the answer at this point.

Keith

Empire_2

My opinion

Delta P you may need an additional flo-check on the ret. leg. SHould solve the problem. Somewhere in that circuit the water wants to flow past the Fc.