Issues with Return AND Away Pumping on same boiler?

D107

3 zones are on return, new HW indirect will be fourth zone pumping away. We may not use DHW priority since boiler is 4x oversized. (Putting off new boiler to when required system piping can be redone.) It occurred to me that with a heat and hot water call at same time (non DHW priority) the pushing and pulling of the opposite pumping configurations could cause some problems. (perhaps DHW prioriy would negate those problems since that would keep return pumping heating and DHW supply pumping separate.

Thanks,

David

Al Letellier_9

pumping away and pushing

As long as the pumps are all moving water in the same direction, you should have no problems. Depending on the indirect and the head loss thru it, the worse that can happen is a potential loss of required flow thru the indirect. Priority control would eliminate that chance.

Al Corelli_2

We do it all the time.

We do not repipe anything old when adding an indirect. We just add it and pump away. It keeps the price down.

As I have seen your system, there would be no problem doing it the way we discussed (leaving the returns small, etc.)

To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"

Unknown

Us too

On existing boilers , we pump away from the boiler and expansion tank for the new indirect . And the heating circs are ALWAYS on the return side .