Where to get info and buy Grundfos Alpha 3 circulator pumps

Chris_51

I've been trying to get info on a direct swap out for a Grundfos UP43-75F. I think my application will be fine with 20 GPM or maybe even 15.

The local guy reads from his computer what is in stock. But can't tell the pipe spacing. The online guy is about the same. He says he is just a distributor.

I have some pumps that are 6.5 inches and some that are 8.5 inches. The 8.5 inch pumps have huge flanges.

Any ideas?

GGross

Grundfos website went through renovation 1-2 years ago and is in my opinion really really bad so I will help you out. Port-to-port length is the value you are looking for

Alpha 2 26-99
https://product-selection.grundfos.com/us/products/alpha-north-america/alpha2-26-99-north-america/alpha2-26-99-f-99490916?tab=variant-specifications

port to port length 6-1/2" availability is pretty sketchy right now

For your larger pumps you would need to move to a magna to get the same port-to-port length, you can plug your duty point into the curve on the 26-99 to see if it will achieve your goals the magna pumps might have a different flange size than your current pumps, this one is the same port to port length, but is a bit more beefy of a pump overall

magna1 40-80
https://product-selection.grundfos.com/us/products/magna-north-america/magna1-north-america/magna1-40-80-f-98126799?tab=variant-curves

port to port 8-9/16 (same as the 43-75)

If you just want a 3 speed replacement for that pump, use this one


https://product-selection.grundfos.com/us/products/up-ups-series-100-north-america/ups-43-north-america/ups-43-100-f-216-95906636?tab=variant-specifications


To check your own pumps curve, on that website select "products and services" then in the drop down again select "products and services" in the "find a grundfos product" field enter your pumps 8 digit product number, your pump in the picture is number 52722373

https://product-selection.grundfos.com/us/products/up-ups-series-100-north-america/up-43-north-america/up-43-75-f-216-52722373?tab=variant-curves

hot_rod

I don't think any of the Alphas come in that 8.5 flange to flange dimension. Maybe some of the Magnas, but they seem to have 4 bolt flanges.

You may need some piping adjustments.
The Grundfos rep or dealer should be able to tell you which pumps have that wider flange to flange dimension. Or spend some time at the Grundfos website.

Some of the old style B&G HVs had that larger flange size, maybe their ECMs do.

Chris_51

Thanks. This info is helpful. The resellers I found drop the port to port spec for their listings. My local supply house had no idea.

I know what to do now.