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Grundfos wet rotor pumps

Alan (California Radiant) Forbes
Alan (California Radiant) Forbes Member Posts: 4,214
in THE MAIN WALL
Have you ever noticed the screws they give you for the covers? Invariable, they strip out before you get the cover secure. We've resorted to having a stock of stainless steel screws just for Grundfos covers.

I looked for a ranting forum, but couldn't find one.
8.33 lbs./gal. x 60 min./hr. x 20°ΔT = 10,000 BTU's/hour

Two btu per sq ft for degree difference for a slab

Comments

  • Alan (California Radiant) Forbes
    Alan (California Radiant) Forbes Member Posts: 4,214
    The threads don't strip. The phillips slots strip before you can get the cover anywhere near tight. The screws are cheap pot metal and even with a good phillips screwdriver, the metal just twists off after some resistance.
    8.33 lbs./gal. x 60 min./hr. x 20°ΔT = 10,000 BTU's/hour

    Two btu per sq ft for degree difference for a slab
  • Tinman
    Tinman Member Posts: 2,808
    Hardest screws to bury on a pump electrical cover, bar none.
    Steve Minnich
  • hot_rod
    hot_rod Member Posts: 23,398
    Alan (California Radiant) Forbes said:

    The threads don't strip. The phillips slots strip before you can get the cover anywhere near tight. The screws are cheap pot metal and even with a good phillips screwdriver, the metal just twists off after some resistance.

    I agree, Alan. I'm not sure it is a true phillips head? New or old, none of the #1 or #2 phillips drivers fit well.
    Maybe it's a Torx or something.
    I'd rather have a a metric allen or slotted head screw. Zip screws work, kinda.

    They have also struggled with wiring connections and terminal strips over the years. They need an installer to design those two components.

    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • BobC
    BobC Member Posts: 5,502
    I see this all to often, they use some crap hardware to save a few cents. It's one thing if it's a $10 item but they get a lot money for those pumps.

    i used to buy hardware for a small production company so I am very familiar with the cost of stainless steel hardware At the production level it would cost 12 to 15 cents to use stainless steel for those three screws.

    Shame on them for doing this on a piece of pricey hardware.

    Bob
    Smith G8-3 with EZ Gas @ 90,000 BTU, Single pipe steam
    Vaporstat with a 12oz cut-out and 4oz cut-in
    3PSI gauge
  • Harvey Ramer
    Harvey Ramer Member Posts: 2,261
    I see I am not alone in my misery.

    I am trying Honeywell pumps on one of my upcoming jobs. They have a label on the junction box where you can write the install date, zone info, etc. Kinda neat I thought.
  • Boiler wrestler
    Boiler wrestler Member Posts: 43
    I suffered as you all have with these screws, then fed up I tried my impact and bam never a tear shed again.
  • SWEI
    SWEI Member Posts: 7,356
    Taco learned a few things from the HEC-2. The VT-2218's are pretty well thought out.

    Grundfos is currently spending some real money re-working the cover attachment on the small MAGNA3's.
  • Tinman
    Tinman Member Posts: 2,808
    edited October 2015
    Another thing I'd love to see changed with that pump - get rid of the tapped/screwed opening for the electrical fitting and use a typical knockout instead.
    Steve Minnich
  • Alan (California Radiant) Forbes
    Alan (California Radiant) Forbes Member Posts: 4,214
    I hope they re-engineer the speed selector mechanism and lever interface as well. It seems so fragile.

    Harvey: Which Honeywell pump are you using?
    8.33 lbs./gal. x 60 min./hr. x 20°ΔT = 10,000 BTU's/hour

    Two btu per sq ft for degree difference for a slab
  • hot_rod
    hot_rod Member Posts: 23,398
    Armstrong got very close to ideal, on their small ECM. Single cover screw that works, plenty of room inside for wire management, multiple holes for linking pumps.

    The spring type terminals are fine for single use, seems if you cycle them a lot they lose interest.

    Odd sized holes for the wiring connection? But they include several adapters.

    A Unibit fixes the undersized hole if you need 1/2 for flex or liquidtite connectors :)
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • Harvey Ramer
    Harvey Ramer Member Posts: 2,261
    edited October 2015
    Alan (California Radiant) Forbes said:

    I hope they re-engineer the speed selector mechanism and lever interface as well. It seems so fragile.

    Harvey: Which Honeywell pump are you using?

    I haven't used one yet but have held it in my hand, looked at it and liked it.
  • Harvey Ramer
    Harvey Ramer Member Posts: 2,261
    edited October 2015
    Deleted, Having connectivity issues. I'll get you a link to the pump yet Alan.
  • SWEI
    SWEI Member Posts: 7,356
    Is that an ECM pump?
  • Harvey Ramer
    Harvey Ramer Member Posts: 2,261
    https://customer.honeywell.com/en-US/Pages/Product.aspx?cat=HonECC Catalog&pid=PC3F1558IUF00/U&category=PC3 Circulation Pump&catpath=1.2.2.20.1&rank=0&v1=Sort.1.Product.Rank&asc=1
  • Harvey Ramer
    Harvey Ramer Member Posts: 2,261
    SWEI said:

    Is that an ECM pump?

    Nada
  • Alan (California Radiant) Forbes
    Alan (California Radiant) Forbes Member Posts: 4,214
    Yeah, I like it!
    8.33 lbs./gal. x 60 min./hr. x 20°ΔT = 10,000 BTU's/hour

    Two btu per sq ft for degree difference for a slab

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