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Spring Coupler

BillEllen Member Posts: 2
Bell & Gossett sells 2 motor/pump couplers for the series 100 heating system motor. Either one may be used. My original is stamped steel and that replacement seems to cost more than the cast iron.
1 - Bell & Gossett 189110 Spring Coupler (stamped steel)
2 - Bell & Gossett 118705 Spring Coupler (cast iron)
I sent an email to B&G asking which one is best to use and why but received no reply.
Which one would a heating system professional choose.


  • AlCorelliNY
    AlCorelliNY Member Posts: 63
    I would choose the one I had in the truck at the moment.
    Usually it is cold, nighttime and snowing whenever I've changed one.
    Al Corelli

  • Ironman
    Ironman Member Posts: 6,685
    I'd add to that: if any other part of the series 100 goes bad, I would replace it with a properly sized wet rotor circulator. That thing is a 1950s technology energy, maintenance hog.
    Bob Boan
    You can choose to do what you want, but you cannot choose the consequences.
  • icesailor
    icesailor Member Posts: 7,265
    B&G has plastic ones, Those were really fine unless you has issues or a larger than normal motor.

    P-3 pumps take a cast iron coupler that is slightly larger and heavier than standard. The only way you could tell the difference was if you had them side by side.

    The part about what is in the truck at the time is true. My supplier only supplied aftermarket couplers. I only bought the heavier kind. The difference in price wasn't worth having to go back for a free service call.