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Noisy Circulator Pump

Hi everyone,

I just bought a house about 6 months ago and now I'm having an annoying problem with the circulator pump in the heating system. I have a closed water heating system, with a circulator pump next to a gas power boiler.

When the pump starts up there is a really loud rattling sound that you can hear in the whole house. I've turned the pump off with its toggle switch when its making this sound and it stops, so I'm pretty sure its the circulator pump and not something else. I've tried bleeding the air from the system (maybe I didn't do this right) at the air scoop, but only water comes out so I don't think its an air problem. I don't know how old the pump is, but its labeled as an Armstrong SS-30 which is supposed to be self-lubricating. Does anyone have a clue what the problem might be here? Do I need to replace the pump or am I just not bleeding the air properly? Thanks for any advice!


  • Mark EathertonMark Eatherton Member Posts: 5,493
    Got pictures????

    There are numerous other devices in the flow stream that can and will cause rattling. Get back to us with a picture of the near boiler piping.

    It's not so much a case of "You got what you paid for", as it is a matter of "You DIDN'T get what you DIDN'T pay for, and you're NOT going to get what you thought you were in the way of comfort". Borrowed from Heatboy.
  • CrabbymanCrabbyman Member Posts: 7
    Not great picture

    Here's the only not so great picture I have of the system right now from our home inspection. I don't know how helpful it is, but you can see the pump on the left. Is there any particular area where a picture would help?

    After the pump is the expansion tank/air scoop and then it goes off to the heating system. Before the pump is the return water pipe and an inlet pipe to add water, then the boiler obviously.
  • Mark EathertonMark Eatherton Member Posts: 5,493

    You're right. Not much to see, although I can tell you that the pump is not in the ideal spot. It is pumping towards the expansion tank, which will work, but it would work better if the pump were pumping away from the expansion tank.

    By having the pump where it is, it is generating all negative pressure, which can cause a pump to make noises that are not normal. Fill pressure will have an affect on this as well.

    I see a lot of rust near the boiler, and that is not normal. Any idea where THAT is coming from?

    The other device that may be present that can cause rattling is a device that is like a check valve (one way valve). It would be down stream of the air scoop and expansion tank.

    If you can take a better picture showing more of the components, it would be extremely helpful.

    It's not so much a case of "You got what you paid for", as it is a matter of "You DIDN'T get what you DIDN'T pay for, and you're NOT going to get what you thought you were in the way of comfort". Borrowed from Heatboy.
  • CrabbymanCrabbyman Member Posts: 7

    I noticed all that rust in the picture too, I think the its from an old water heater that was replaced before we moved in. You can't see it so much in person.

    I'll take more pictures when I get home and put them up. I might have the water direction wrong, I can't remember off the top of my head if the pump is before or after the tank, but that's the general setup.

    I'm not aware of a check valve, but I was looking mostly around the pump for problems so I might have missed it. The noise sounds like its coming from the pump or at least that area, and like I said when I turn off the pump the noise stops.

    Thanks for the help! I'll take more pics when I get home.
  • CrabbymanCrabbyman Member Posts: 7
    More pictures!

    I got some more pictures of the system. I was wrong earlier, the pump is before the expansion tank in the system. Here are some of the pictures I got, let me know if any other angles or areas would be helpful. Thanks!
  • Wayco WayneWayco Wayne Member Posts: 2,458
    I once had

    a noisy circulator on a system that I couldnt figure out right away. I finally drained the whole system (no circ flange ball valves Ack!) and took off the motor, only to find some little pellet balls of solder were stuck in the impellar paddles. They must have traveled from where a repair was made and affter wedging in the impellar made it spin off balance and made quite a noise. I popped them out with a little screwdriver and it worked fine after that.
  • Mark EathertonMark Eatherton Member Posts: 5,493
    Don't see any gravity checks...

    So it must be the pump, and at least you do have necessary isolation to avoid having to completely drain the system to pull the pump and see what's up.

    It's not so much a case of "You got what you paid for", as it is a matter of "You DIDN'T get what you DIDN'T pay for, and you're NOT going to get what you thought you were in the way of comfort". Borrowed from Heatboy.
  • CrabbymanCrabbyman Member Posts: 7
    edited February 2011
    Thank goodness

    Thank goodness for the isolation valves, though I don't mind too much if the basement gets soaked anyway.

    I guess the next step might be to pull the pump and poke around to see if I can find anything that looks wrong. I think I should be able to just leave the flanges on the pipes and pull just the pump and motor portion off at the allen screws, but maybe I'm wrong. The pump ran fine for about a month, then made the noise for about a month, then stopped for a few weeks, then started up again so I think its the bearing going out, but poking around might reveal something.

    I've been looking at new pumps on Armstrong's site, but it seems like all the flanges are off by 90 degrees from what I have. It seems to me that I can just turn the flanges that are on the pipes to get them to line up since they're screwed on, or maybe I'm just looking at the completely wrong models. Anyone know anything about that in case its something I can easily fix in the pump?

    Thanks all for the help, I'm probably just going to wait until it gets warmer to even fiddle with it in case I break it worse.
  • BigRichBigRich Member Posts: 3
    noisy pump

    The Armstrong SS30 was discontinued about 10 years ago, the replacement for it is the Astro230CI and is aslo available with a rotated flange which is the Astro 230CI-R, they are available thru most local wholesalers
  • CrabbymanCrabbyman Member Posts: 7

    Thanks for the information, big rich! I'll look into it. I had no idea what to call the flange direction when trying to describe it to someone.
  • CrabbymanCrabbyman Member Posts: 7
    Quick Update

    Just wanted to leave a quick update for anyone else that googles this. Turns out it was the circulator pump. I replaced it with a Grundfos UPS15-58FC, since the armstrong pumps are harder to find, and now the system is completely silent. Thanks for all the tips!
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