Circulator pump location

Temple89

I got called out on a no heat call today. Turns out a couple zones need to be purged. These are two boiler piped together and it seems like one boiler is constantly on and doing all the work. The other reaches hi limit and doesn't seem as if its circulating. I think one circulator is in the wrong location and should be before the "Tee" joins the feed piping of the second boiler.I'm posting some pictures please let me know what you guys think.

SWEI

Missing items

at first glance:  Isolation valves, check valves, primary secondary piping/pumping, and probably staging controls.



It looks like the factory-provided boiler circulators (at least one of them) are still on the return, with the two Taco pumps (presumably pushing into the distribution loop) then acting in series with the boiler circs.  Got a sketch?

Unknown

patheic

Of course the new boiler won't fire up..

Unknown

patheic

Of course the new boiler won't fire up..

hot_rod

parallel pipe

is fairly simple. If they are connected to radiant or high mass rads, return protection may be needed. Fin tube or air handlers could be piped direct.

Temple89

Diagram

Here's a sketch of the circulator locations. Zones go to fan coils and 3 small radiant loops. Boiler one constantly runs while boiler two reaches high limit and water doesnt circulate through. If I move the circulator on the feed of boiler one. And move it to the return of boiler two it should solve that problem? Also need to add spirovent and isolation valves.Let me know what you think thanks

Temple89

Diagram

..

Unknown

nope

Nope... did you really piped this system??? The pipe is undersized for the system..

Temple89

No

Rjb, I was called there to purge a few zones. I'm trying to get him to fix this problem. You seem very knowledgable. What would you do?

RobG

Don't Know

I don't know if it makes a difference with individual boiler pumps, but with multiple boilers and a single pump, I was taught to pipe in reverse return, so that's how I pipe all multiple boiler installations. That said, do it just like Hot Rod's diagram, but maybe in reverse return? (don't listen to rjb, he only seems to be able to offer criticism, not help).



Rob

SWEI

There are three pumps

and two boilers, apparently of different sizes, and no hydraulic separation.  Time for a re-think IMO.

Unknown

correct, SWEI

Correct... pipes are undersized to begin with.. imo.. the larger boiler is large enough to handles the load.. don't need the improper piped secondary boiler.. homeowers here can't handle my criticism because they know so much more than me.

RobG

System

I don't believe the OP is a homeowner, but a fellow tradesman looking for advice.The day you stop learning something is the day it's time to find a new career.

Rob