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Grundfos Pump motor

I have (had) a Grundfos cartridge circulator pump. Bronze housing. Got it cheap somewhere and have had it circulating water in my heating system for 3 or 4 years now.

  Problem occured a while back with a poor connection in a electrical box and the motor on this pump bore the brunt of the electrical load for the system and burnt the motor up. I had wired the 4 neutrals of this system together in the breaker box and neglected to tighten the screw on them down, and over the years the joint heated up from the poor connection and this was the result. I fixed the wiring problem, now I need to see about the pump.

  I have the pump off at a motor repair shop and they are looking at it. They told me awhile back that their Grundfos contact company had a breakup with Grundfos and they are not sure they can get replacement parts..

  What I want to do is get a new motor- the pump impeller, cartridge, and related housing parts are pristine, I just want to see if I can get a replacement motor to get the thing back up and running.

  I don't have it here in front of me to get a model number, but even so I haven't been able to run down a place to buy just a new motor- or stator or whatever I should call it. If I could find a used pump with a bad rotor or whatever, I'd take that motor off and substitute it on this bronze pump and get going.........

  Can anyone steer me in the right direction, to the right distributor or parts house? Surely it would be cheaper to buy a new "motor" and slap it on this bronze housing than to buy another bronze pump.


  • JoeKansas
    JoeKansas Member Posts: 14
    Well, anyway..........

    I guess I'll answer my own question. I called a place I saw on the net, who seem to have lots of hydronic heating stuff~ Patriot Supply~ and told the man on the phone what my problem was.

      He said there are no replacement motors for the all in one pumps- the cartridge pumps.

      As soon as I can get the pump back from the motor shop, I will take note of the pump number/style and keep an eye on ebay for one (with cast iron body and hopefully in used condition and not new) and strip the stator from it and rebuild my bronze pump.

      Thanks anyway..........
  • EricAune
    EricAune Member Posts: 432
    Why bronze?

    Is your system subject to oxygen diffusion? Is it an open system?  if not, why not just replace it with a lesser cost cast iron circulator?

    If you do need a bronze body circ, get the numbers off the housing and buy the exact replacement with a cast iron body.  I would recommend buying new at this point, getting someone else junk is exactly that most of the time.

    There was an error rendering this rich post.

  • JoeKansas
    JoeKansas Member Posts: 14
    Not quite open

    I want to keep the bronze pump because it circulates water from a wood fired boiler. It's not quite open to the atmosphere, but I got such a good deal on the pump I hate to let it go. I have the boiler is a closed system, but I made a fitting on the top of it that has a 12 pound radiator cap installed on it, and the radiator cap is the type that won't let air back into the system when the fires' out and the water level drops a bit when it cools off. It creates a vacuum, actually. I have a pressure/vacuum gauge mounted on the top of the boiler, and in the summer it shows (and holds) a vacuum of about 5, according to the gauge.

      This bronze pump circulated water thru a heat exchanger to cut down on gas usage by my Munchkin as it heats my house.

      After this pump failed, I took a cast iron pump out of the house heating system that was in the domestic hot water side of the system (that I disconnected because I went tankless) to use in place of the bronze pump. This pump circulated boiler water thru a Superstor tank. When I got it disconnected, I find that rust had built up in the pump. This system IS closed.  I cleaned out all the rust I could and flushed the pump housing out good and installed the pump and went on.

      The closed system had a leak- at the threads on some of the Chinese pipe fittings, go figure- for a few years and every month or so I would add water to the system to replenish it. Got the leaky threads sealed now, added water, and I should be good to go.

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