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Thread: Broken Pump or Blocked Pipe?

  1. #1
    Tosai
    Join Date
    Mar 2006
    Location
    New Jersey
    Posts
    15

    Broken Pump or Blocked Pipe?

    I just fired up the pond for the spring and something strange is going on.

    The falls are going very, very slow.

    The pump is a sequence 1000 connected to a 3-chamber spirex vortex filter system.

    When I plug it in, it sounds normal, like it is running fine, but the flow rate is about 1/10th of what i normally get.

    This kind of thing has happened before, but it was always because something got clogged in the intake of the pump. I checked the pipe going into the pump, and water seems to be flowing just fine into the pump.

    The pump is below the water line, so there is constant gravity feed going into it.

    The pump is going on 8 years old, so I expect it will just fail at some point.

    I am tempted to just order a new pump, based on the age, but i don't want to do that if the pump is not the problem.

    Anyone have experience enough with pumps to tell if my pump is "on-th-fritz" and about to die on me, or if it's likely something else? (maybe something got cloggged up in a pipe somewhere over the winter?)

    Is a pump an a "all-or-nothing" device? In other words, if it is working at 1/10th it's normal strength, is it still "working" and the problem is something else, or can the pump "fade away" before it completely craps out on me?

    any insights appreciated!

  2. #2
    Daihonmei dick benbow's Avatar
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    Dec 2003
    Location
    seattle, wa
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    6,340
    pumps like koi are hard to diagnose without being there. I still have my original sequence i bought dcades ago. Runs fine. I have a brand new one in the box never used so kinda don't believe that's the problem. Would suspect something is in the input line or housing. With pumps you can restrict output up to half but don't want to deny any input. So don't run till you know what it is. I'd be tempted to pull it off line ( hopefully you have quick dis/ connect ) and check by blowing back the input line and making sure nothing in propeller.

  3. #3
    Daihonmei PapaBear's Avatar
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    Oct 2005
    Location
    Davenport, Oklahoma
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    6,726

    I'm with Dick...

    Bits of gunk can get stuck in the impeller and slow things down dramatically. I don't have a sequence so I can't give any detailed suggestions, but backwashing through the pump to dislodge any debris sounds like a good idea.

  4. #4
    Oyagoi bekko's Avatar
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    Sep 2004
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    Hakipu'u
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    1,383
    First, make sure the pump is not air locked. Restart it a couple of times.

    If there is something lodged in there, it's more likely in the pump than the pipe. Unless you have a check valve, the smallest constriction is the pump impeller so that is where you are most likely to have something lodged. The impeller speed is all-or-none unless it is slipping on the shaft (unlikely). A bad shaft bearing could also cause it to run slow, but you would hear a grinding noise and the motor would get hot and kick off on the thermal overload.

    I agree with Larry. Push water backward through the pump if you can.

    If that doesn't work, remove the suction pipe and unbolt the pump head. There are six nuts and bolts holding the two halves of the pump head together. After removing the bolts, you may have to use a screw driver to work the front half of the pump head off. The back half of the pump head, shaft and impeller will remain attached to the motor.

    If there is nothing lodged in the pump head, turn the impeller with your finger and/or briefly plug in the pump while the front hald of the pump head is removed. The impeller should turn freely.

    If that is not the problem, then you will have to start pulling the plumbing apart or run a snake through the lines.

    -s

  5. #5
    Honmei
    Join Date
    Sep 2005
    Location
    Martinez,CA
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    4,611
    There have been times when backwashing my pump has not worked. I have had to open the impeller housing to clean it out.

  6. #6
    Tosai
    Join Date
    Mar 2006
    Location
    New Jersey
    Posts
    15

    Blocked Impeller Blades

    Yep... when I pulled out the pump and took off the housing, there was a big mess of leaves and twigs that were clogging up the impeller blades.

    Must have gotten past the skimmer over the winter somehow...

    Hey, this post saved me from replacing the pump!

    Thx for the insights!

  7. #7
    Daihonmei dick benbow's Avatar
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    Dec 2003
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    your welcome

  8. #8
    Oyagoi bekko's Avatar
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    You must have a small basin at the top of the waterfall where the water enters. When you shut the pump off, the water running back down the pipe feeding the waterfall started a siphon and sucked the debris out of the basin at the top of the waterfall.

    -ste

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