Re-Circ pumps?

[bhamiltonjr]

What are your thoughts on a Grundfos Re-circ pump that has a manifold installed under furthest fixture and is only a 3/16 HP Pump? I have installed a few so far and havent heard any complaints. Nor have I followed up with where I installed. I have talked with Grundfos and they insured that they work great so long as you dont run them 24/7. But re-circs through the cold line. Any thoughts on a better product like a Motion sencer style or a "true recirc that has a loop that dumps back into a bottom of a W/H. Your opinions and thoughts would be great feedback. Thanks/\.

 

[johnjh2o]

The re-circ system that uses the cold water line works OK. But the better system is one that uses a designated re-circ line. What happens when using the cold line you get some hot water that mixes with the cold. It's not a lot but it is noticeable. When possible I would run a designated line but in many cases that's not possible. In that case the Grundfos system is better then nothing.

john

 

[desertwater]

Yes a designated loop is the best. I have installed many comfort series pumps and have been told to install them with two loops, one at the closest fixture and one at the furthest fixture. I did this install on a 4,000 sq ft. house with a finished basement. I put one in the hall bath closet to the water heater and the other in the basement and to my surprise it worked great! Got hot water in about 15 seconds versus 3 min. In the basement. i have also been told that no more than two loops are necessary. I havent looked to much into it but the two loop system seems to work, customer was thrilled!

 

[Another-Plumber]

Opinion time, do you prefer to push or pull the water

 

[desertwater]

Opinion time, do you prefer to push or pull the water

Ive been told to push the water because it has more resistance. But I couldnt tell you exactly why.

 

[phishfood]

Maybe I am not thinking about this correctly, but with a recirc system, all you are doing is creating a slight pressure differential, not flowing anywhere near the flow potential of the pipe, so it shouldn't matter.

 

[Mr_David]

I agree with Phish. Recirc pumps don't really push the water. It moves it by cupping it.

 

[bhamiltonjr]

its like a pool pump system or a close railroad track system. Cause the pull or push doesnt effect anything becasue rather its a loop it comming from the end of a hot main line or a mainifold system its going through the cold line back to w/h.

 

[desertwater]

Maybe a difference if the pump is on the return side or the supply side. Idk.

 

[Caduceus]

In a closed water distribution system, I would think that the return side and the supply side are one in the same as far as hot water recirculating lines are concerned.