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Milwuakee M18 Transfer pump to add antifreeze

joeba
joeba Member Posts: 23
Anybody have luck using this pump to add antifreeze to a system? I have an AH in the attic and I'm not sure this pump will do a good job of purging. Specs are 25PSI at 0 with a max head of 75. It seems to be equivalent to those small electric 1/10 HP pumps. Maybe it's time to invest in a Liberty 331?

Comments

  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 3,640
    edited September 15
    If the system is already full of water (in operating condition) and all you want to do is add antifreeze while removing an equal amount of water at the same time, the answer is YES. The weight of the water going up will be offset by the weight of the water going down the other pipe. When the water coming out starts to change to the color of the antifreeze then it is time to stop.

    If the system is empty (completely, like just installed and it might even have air pressure test on it), then the head pressure of the pump must be at least a little more than the hight of the top water component. So, if the pump has a 75 ft head pressure rating, then you should be able to move water up to the attic with no problem, unless the attic is located 80 feet above the pump location.

    Why do you ask?
    Edward Young
    Retired HVAC Contractor from So. Jersey.
    Services first oil burner at age 16
    P/T trainer for EH-CC.org

  • hot_rod
    hot_rod Member Posts: 16,878
    If you have a zone with problematic air, you want a pump to push enough flow to get over 4 fps velocity.
    For a good complete flush and purge. It's the down-coming pipes that are hardest to flush if you don't have enough velocity the air floats up as flow comes down.

    With a 3/4 copper M loop you want around 7 gpm, or more. Sadly that pump will not do it. Even with a new battery I get around 17 minutes run time from my Milwaukee, performance drops as the battery weakens. Wear ear plugs if you use that pump :)

    8-10 gpm is easy for that 331 or equal. If it is a one time use, a small inexpensive 1/2 hp sump pump from the box stores works also, throw it right into a 5 gallon bucket to p[urge so you can see when the air bubbles stop flowing.

    Glycol doesn't give up air very well, it could take a while for the cloudy-ness to go away while purging. And after it heats up, you may need to purge again as the entrained air only comes out of the stuff with heat.
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • SuperTech
    SuperTech Member Posts: 1,804
    I've used that pump for a few years now with the big 12.0 batteries. It works well, my only criticism is that I have to relubricate the impeller quite often. 
  • hot_rod
    hot_rod Member Posts: 16,878
    SuperTech said:

    I've used that pump for a few years now with the big 12.0 batteries. It works well, my only criticism is that I have to relubricate the impeller quite often. 

    It's a rubber paddle displacement style pump and the paddle needs to be kept wet.

    Plenty of good applications for that pump, draining water heaters, pumping out toilets, small boiler fills.
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • joeba
    joeba Member Posts: 23
    I already own the pump and have found it very handy, but I did not think it had enough juice to purge so that is why I asked the question. To get around this, I found this alternative method of adding antifreeze. Totally fill the boiler and heating loops and purge it out real well. Then run it up and make sure the air is all out and then shut the valves on the supply and return. And then drain down the boiler. Then I’ll use the M18 pump to fill the boiler from the bottom, removing an air vent on the top of the air scoop and fill it until the antifreeze comes out the vent hole. Then bring the boiler up to pressure and open the valves and run the systems zones. This will mix the antifreeze in. BTW, 5 gals of Cyro-Tek 100 cost me $72 back in 2019. Cost me $137 today. Don't want to waste any of it.
  • joeba
    joeba Member Posts: 23
    FYI, you can find replacement impeller on Amazon and other places ..
    https://www.supplyhouse.com/Milwaukee-49-16-2771-2771-20-Replacement-Impeller-Kit-Pre-Greased
  • hot_rod
    hot_rod Member Posts: 16,878
    joeba said:

    I already own the pump and have found it very handy, but I did not think it had enough juice to purge so that is why I asked the question. To get around this, I found this alternative method of adding antifreeze. Totally fill the boiler and heating loops and purge it out real well. Then run it up and make sure the air is all out and then shut the valves on the supply and return. And then drain down the boiler. Then I’ll use the M18 pump to fill the boiler from the bottom, removing an air vent on the top of the air scoop and fill it until the antifreeze comes out the vent hole. Then bring the boiler up to pressure and open the valves and run the systems zones. This will mix the antifreeze in. BTW, 5 gals of Cyro-Tek 100 cost me $72 back in 2019. Cost me $137 today. Don't want to waste any of it.

    How do you know what % you end up with. You'd hate to purge out glycol to boost the mix % up. Or down :)
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • joeba
    joeba Member Posts: 23
    I broke down and purchased the liberty 331. It worked like a charm, especially during the purging phase. With the M18, during the purge, it was not very strong and it could not keep up with the return. I do have an air handler on the 3rd floor, so the m18 could work with a smaller home. BTW, I finally read the label on the lid of the Cyro-Tek 100 (after using it for 10 years :-() and noticed the refractometer correction table. So instead of getting 12 degrees of freeze protection with my 50% dilution (of 55% glycol) I am getting 3 degrees with -20f burst.
  • hot_rod
    hot_rod Member Posts: 16,878
    Yes you want to read the label on the bucket, not all glycols come at the same strength. Which is usually reflected in the price of the fluid :)

    The top brands, like DowFrost HD, Rhomar Rho GuardUltra, it's rare to need more than 40%

    RhoGuard Ultra at 40% is -3 and -60F burst
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • hot_rod
    hot_rod Member Posts: 16,878
    Another reason not to get to rich of a %

    In this example at 50% , a 66% increase in wattage!
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • joeba
    joeba Member Posts: 23
    The little 007 on my system not exactly putting me in the poor house, but an interesting point you bring up.