Two temperature boilers plumbing circulator location

Kkane97

hot_rod said:

You need  to pump away from the mix port of a 3 way valve. This allows it to pull from the H &C port of the valve

I scrolled back up and reread all the above I misunderstood when I was initially asking if it was ok to have the circulation on the return side and now see everyone was saying it's better like you stated. Now I'm pushing the cold and pulling on the mix

hot_rod

Kkane97 said:

Ok thank you for explaining, since I am able to maintain my mixed temperature would it be ok to leave as is until I decide to change the rest of the house to infloor heat? Or switch around now. 

No harm in trying it like it is. I suspect the temperature will be erratic, bouncing above and below setpoint. As long as it keeps the space warm, give it a go.

When you do a major repipe, post your plan heard for some feedback

EdTheHeaterMan

@Kkane97 I appears that Bob (Hot_Rod) is saying that your design will work.

However, there may be Air problems since all your circulators are on the return side of the system. If you have the time and can re-design the pumps to be on the supply side, pumping away from the expansion tank, then you will have designed as system that will eliminate air by design. Currently you have a system that may cause air to get sucked in as the system operates. Eventually the air may cause a problem until you manually purge it from the system from time to time.

Kkane97

The cap on my supply and return I left for a heat exchanger to a outdoor wood stove I am planning on setting up. I was hoping my repiping I did was correct and could tie in a heat exchanger to the supply cap shown at the drop and switch the elbow out on my threaded return side for a tee and tie in there with another circulator for the outdoor unit. Will definitely hold off on cutting pipe until I fully draw it out. Thank you again, so far a great learning experience and this site has been a wonderful resource

Kkane97

EdTheHeaterMan said:

@Kkane97 I appears that Bob (Hot_Rod) is saying that your design will work. However, there may be Air problems since all your circulators are on the return side of the system. If you have the time and can re-design the pumps to be on the supply side, pumping away from the expansion tank, then you will have designed as system that will eliminate air by design. Currently you have a system that may cause air to get sucked in as the system operates. Eventually the air may cause a problem until you manually purge it from the system from time to time.

I don't mind complete redoing everything again🤣 I enjoy projects like this, just turns into more practice. Thanks

EdTheHeaterMan

In the Hydronics class I taught for EH-CC.org I copied an idea from @DanHolohan's seminar on pumping away. This is a pumping away module


If you were in the business of installing boilers you could make these up in the shop and bring them prebuilt to the job and save time.
this is the next slide in the presentation



I have made some alterations to make it more like your system.


The pumps can be on the horizontal or the vertical. Just make sure the motor is not on top or bottom when on the horizontal, Must be to the left or right (9 o'clock or 3 o'clock) position

Kkane97

@EdTheHeaterMan I have read that as far as circulation direction, do you know what the issue is as far as pump orientation?

EdTheHeaterMan

Yes I Do. Since these are wet rotor they depend on water to surround the rotor for lubrication. If you install the pump so the motor is up, there will be an air bubble at the top of the pump housing and that will cause excess friction and premature failure. if the pump housing is pointing down, then rotor will be falling away from the bearing and overheat causing premature failure. on the 45° will also place excess stress on the bearing. Horizontal motor is the only correct way to install a wet rotor pump.Taco and B&G also have similar instructions.