Print

[gravinus]

Hello Everyone!

I just built a home in Minnesota and the builder ran some of the plumbing for my wood boiler (I've attached a picture). Basically, the circulation pump (P1) is in the basement and will run 24/7. This is an M&J boiler and it didn't have an option for an internal pump. There is also a booster pump (P2) that is located just above my forced air furnace and will come on when the furnace calls for heat.

My initial thought was that I will need a zone valve to close the circulation loop off and force all the water flow to the booster pump (P2). Does anyone have any thoughts on this arrangement?

Thanks, Ben

[RSI]

Is it that big of a deal to you to not circulate through the heat exchanger all the time? Most do. You get a little convection heating when the blower isn't going but not that bad. Not usually noticeable except early spring and late fall when it gets hot during the day.

[gravinus]

Thanks for the reply. I guess my preference would be to not flow through the exchanger all the time as we might run the boiler a bit longer into spring/fall if we hook a hot tub up to it.

I think that was the intention of the plumber with this set-up. When the booster pump (P2) isn't running, there wouldn't be any flow. Although, I would think there would still be some through the idle pump. My other concern is that there is nothing to force the water into the exchanger when it is calling for heat except the suction from the booster pump (P2). Some of the supply could bypass this loop entirely.

Do these seem like valid concerns, or do you think I should run the system as is with no changes or actuated valves?

Thanks Again,
Ben

[RSI]

Just get a 3 way zone valve then and skip the second pump.

[Scott7m]

the convection heating is very very minimal, hardly noticeable.   However in that case you could put a t in before the exchanger that cuts across to the exit side of your heat exchanger and have ball valves there to redirect flow in the fall and spring if you wanted.  I often install them like that for folks who want to heat there water in the summer.  That way the pump still runs 24/7 but bypasses the exchanger right before it enters it

[gravinus]

Thanks for the info guys! I've already ordered the 3-way valve so I think that is the route I will end up going. In regards to the second booster pump, it is already installed and wired. Does anyone see an issue with having 2 pumps running in series when the system calls for heat? My thought is to just keep it in and it would increase the water flow and speed up the heat transfer?

Thanks Again,

Ben