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B&G Coupler Assembly

jacobeis Member Posts: 1
I have a 1 1/2 HP B&G Pump for my heating system I oil it once before the new season BUT
at least ONCE a year I have to replace the COUPLER ASSEMBLY i have no idea it broke till my house won't get warm
what am i doing wrong


  • Ironman
    Ironman Member Posts: 6,868
    Probably too much oiling. Your motor mounts are worn (probably from oil) and the motor is mis-aligned with the pump. If the pump shaft turns freely, replace the motor grommets and coupling.

    If the pump goes bad, install a wet rotor circulator like a Grundfos ups15-58.
    Bob Boan
    You can choose to do what you want, but you cannot choose the consequences.
  • kevink1955
    kevink1955 Member Posts: 79
    You probity have sagged motor mounts, they get soft when they get oil soaked. Do your self a favor and look up spiralink coupler they last much longer than the B&G 2 springs. Even better, replace the entire pump with a Taco 007, save you some power cost to.
  • HomerJSmith
    HomerJSmith Member Posts: 1,563
    If it B&G 100 series pump, it has a flat pump curve which works well with zone valves without a differential pressure valve. The Grundfos up15-58 is a high head pump and has a steep pump curve and with zone valves may require a differential pressure valve to minimize excessive flow as the zone valves close down.

    The shafts between the motor and pump must be aligned. Any misalignment will stress the springs and lead to premature failure. If the pump bearings or ceramic seal are too tight, there maybe rotational friction that is putting extra tension on the springs. Look at the pump and make sure it is rotating freely and rebuild the pump if it isn't.
  • Gordy
    Gordy Member Posts: 9,514
    Make sure if switching to a new pump you match curves. The series 100 hv has a different curve than the 100
    EBEBRATT-Ed Member Posts: 12,007
    Is that one and one half horsepower?? If it is it must be commercial or a really big house.

    Are you putting the right coupling on? B & G has different rotation depending on the size of the pump
  • kevink1955
    kevink1955 Member Posts: 79
    I took it to be One Twelfth HP, a standard B&G 100 pump
  • Gordy
    Gordy Member Posts: 9,514
    Probably the hv is 1/6 th