Second pump and new zone for basement finishing

[wellpoison]

I believe I have finally figured out my plans for my basement heat system add on. But I would like as many second opinions as I can. And I know there’s a lot of good, knowledgeable guys on here. Before you say “whoa, this isn’t garage related.” Just know that my large gun/reloading room will be down here, as well as a small shop in the boiler room.

My house right now is heated with an oil boiler, pump through design with two zones, and an aqua stat for domestic hot water supply that I only use when I need to heat my house, otherwise I use an electric water heater. I am finishing the entire downstairs and am looking to add a pump and zone strictly for the basement.

I will add a second pump in parallel with the exsisting pump but will have to put two check valves on each pump outlet to make sure the flow from each flows through the boiler. Then on the outlet of the boiler it should be as simple as installing another zone valve then running my pex to each baseboard unit in series and then returning that line back to the “in” only on my new pump.

Here is the part that I’m a little questionable about. Because my boiler uses an aqua stat and maintaines a certain internal temperature all the time, would I be safe to use my own pump control? Meaning that when my thermostat downstairs calls for heat it would be as simple as a relay that opens the valve and closes the pump contacts, with nothing telling the boiler to “fire.”

I am I wrong thinking that this will work? I am looking into the future with this plan as well. At some point down the road I will be installing an outdoor boiler and as you know that would tie into this system pretty easily.

Thanks guys! And Merry Christmas

 

[Firebrick43]

Is your aquastat in the boiler itself and has a dhw coil installed? Or in an indirect tank?

Is your current system one zone with a zone valve and pump????? Typically people zone with either zone valves or pumps not both.

Most wet rotor pumps included a removable check on the outlet of the pump. The wording you gives sounds like two per pump but I assume 1 for each pump?

Also as written it sounds as if you want to pull water by putting the pump at the end of the circuit instead of the recommended method of pushing water from the manifold to the system.

 

[wellpoison]

The aqua stat is in the boiler itself and does have the DHW coil.

My current system is one pump with 2 zones and a valve for each

Correct 2 check valves, one for each pump.

When I think about it, from my experience I can’t really understand why the pump is where it is and why it pumps through the boiler instead of pulling from it, but that’s how it is.

Every kind of pump that I have ever come across has pulled from some type of reservoir, pumped it to wherever and if it returned, it was returned to that same reservoir.

 

[Firebrick43]

So do you have a zone controller now or are the zone valves actuated by a relay/thermostat directly? How is the current pump controlled?

 

[Kaizen]

redo your existing plumbing. mine comes out the bottom of the boiler and goes up to one circulator. from there it branches to 3 different zone valves. one is triggered by an indirect water heater and the other two zones work off thermostats. I used a ac/dc converter to power all 3 zone valves. backflow preventers are a good idea but with zone valves i don't feel they are needed. i've actually had a problem before where it froze shut. the boiler does not fire unless being called. Wiring is a little complicated.

edit....i tried using pex one time as you describe. pita. big wet noodle. go copper for this instance between baseboard runs if you can. Yes it has its place like when i ran it up in a wall to a wall heater on the 2nd floor. I only used 1/2 inch on that. 3/4 actually ripped itself off the ceiling in the basement and for some reason froze before any copper. oh and a big issue is if it does freeze you can't just put a torch on it to thaw it.

 

[Petro55]

I believe I have finally figured out my plans for my basement heat system add on. But I would like as many second opinions as I can. And I know there’s a lot of good, knowledgeable guys on here. Before you say “whoa, this isn’t garage related.” Just know that my large gun/reloading room will be down here, as well as a small shop in the boiler room.



My house right now is heated with an oil boiler, pump through design with two zones, and an aqua stat for domestic hot water supply that I only use when I need to heat my house, otherwise I use an electric water heater. I am finishing the entire downstairs and am looking to add a pump and zone strictly for the basement.



I will add a second pump in parallel with the exsisting pump but will have to put two check valves on each pump outlet to make sure the flow from each flows through the boiler. Then on the outlet of the boiler it should be as simple as installing another zone valve then running my pex to each baseboard unit in series and then returning that line back to the “in” only on my new pump.



Here is the part that I’m a little questionable about. Because my boiler uses an aqua stat and maintaines a certain internal temperature all the time, would I be safe to use my own pump control? Meaning that when my thermostat downstairs calls for heat it would be as simple as a relay that opens the valve and closes the pump contacts, with nothing telling the boiler to “fire.”



I am I wrong thinking that this will work? I am looking into the future with this plan as well. At some point down the road I will be installing an outdoor boiler and as you know that would tie into this system pretty easily.



Thanks guys! And Merry Christmas

Sent from my iPhone using Tapatalk Pro

 

[Jackfre]

I too think you would benefit from a re-pipe of the near boiler piping. "Pump away" is where you should be. Expansion tank and air eliminator on the suction side of the circs. Also, I think you would see a benefit from dropping the tankless coil for HW and going with an indirect water heater. Check out Taco Zone Controllers fro some control options.