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grundfos alpha pumps ???

any of you familiar with them ???? im not ... and the company i work for is starting to push them on installs. ive already changed two dead ones and have noticed a few that chatter and blink even when there is no call for heat . would love some input on them and any issues that you guys have had with them ?!?! are they ground sensitive ??? best applications ??? ect .


  • Big Ed_4
    Big Ed_4 Member Posts: 2,785

    They used for zone valve applications to maintain proper flow if one or multiple zones are calling. It's a variable speed pump with delta temp and pressure sensors ... You may have a bad end switch or short for the flicker ... I found no issues so far ...
    I have enough experience to know , that I dont know it all
  • ChasMan
    ChasMan Member Posts: 462
    The flicker

    The flicker is more noticeable on a retrofit application. Without ever powering them, straight out of the box and putting them in the system, as soon as you put water in them, they light up like a christmas tree for a sec. THey stop doing that. I imagine there is some residual power in a capacitor or something left over from testing. After they are wired in and powered you won't notice it unless you turn the power off and push water through them. They will repeat the flicker. Doesn't affect operation at all. I have only had three, one of them lasted about two months. The other two are still ok. And yes, they chatter a lot more than the old ones. The checks in them are the same but the pump doesn;lt hold them open quite as well.
  • meplumber
    meplumber Member Posts: 678
    Something they don't mention in the literature.

    The alpha needs power all the time. If you try to drop out power like you would a normal circ, it causes all kinds of problems.

    Provide constant power and let it react to the zone valves opening and closing.

    Good Luck
  • Zman
    Zman Member Posts: 7,569
    It's a delta P

    The alpha does not read the temp. It works off a delta p reading, it comes up with electronically. It won't function well in "auto adapt" mode when switched because it resets what it has "learned" when it is powered off. I like to switch the pump and put it in constant pressure mode. Never had a problem.

    This is not a delta t pump. Taco and others make some nice delta T's for that.
    "If you can't explain it simply, you don't understand it well enough"
    Albert Einstein
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