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Thread: Sudden Pressure Drop

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    Sudden Pressure Drop

    Hello-
    I have been running a Pentair SuperFlo pump for over a year now without a problem. The normal PSI is somewhere around 13-15 and I backwash it when it gets up to 20 or more. Just today I got home from work and noticed the pressure has fallen to around 5 which it has never gone down before.

    2 things, I recently noticed that the basket attached to the pump has a 2-3 inch vertical crack in it. Also, we have had a ton of leaves dropping recently. I'm pretty sure that something is clogged in the pipes and I would like to try and get it out myself if possible but don't know where to start.

    Also, is the crack in the basket a big issue? Can debris get into the motor and if so should I shut it off until I get a new basket?

    Thanks for the help.
    22000 gallon, vinyl, 1.5HP Century Centurion Pump
    Hayward Sand Filter (no.20 silica sand)
    PoolVac Plus Automatic Cleaner

  2. Back To Top    #2
    Most likely, leaves have made their way through - have you looked into your pump basket - likely, it's jam packed full, just remove the pump lid and empty the basket and replace your skimmer basket with a new one.

    I doubt that the pipes are clogged.

  3. Back To Top    #3
    Yeah all the baskets are clear of leaves. The pump seems to be flowing fine (only a small air bubble seen in the clear top) but the pressure reads 5 which is 10 below the normal level.
    22000 gallon, vinyl, 1.5HP Century Centurion Pump
    Hayward Sand Filter (no.20 silica sand)
    PoolVac Plus Automatic Cleaner

  4. Back To Top    #4
    JasonLion's Avatar
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    The two most likely possibilities are, either the gauge is broken or the pipe from the skimmer to the pump is clogged. How is the water flow comming out of a return? If you still have good strong water flow then it is probably the gauge. To try and clear out the pipe you could get a drain king, hook that up to your garden hose, and get the drain king into the inlet pipe at the pump (you may need to remove the pump strainer basket to get full access). If there is something blocking the pipe that will usually blow it out.
    19K gal, vinyl, 1/2 HP WhisperFlo pump, 200 sqft cartridge filter, AutoPilot Digital SWG, Dolphin Dynamic cleaning robot
    Creator of PoolMath and Pool Calculator. Other handy links: Support this site, TF Test Kits, Pool School

  5. Back To Top    #5
    Here's a quick test - first test the flow pressure at the return - does it feel normal - you'd definitely feel the low flow of 5 compared to 15? If you got strong flow at the return it is definitely the gauge - just buy a new one they're cheap - usually only last a year. Sometimes it's a piece of debris that got stuck at the gauge inlet that can cause this - have you tried removing the gauge - letting some water squirt out the hole by turning the pump on briefly and reinstalling the gauge?
    You can fix a gauge too if you feel like it, but that's a different thread...
    If it feels low, set the filter to circulate or whirlpool - this bypasses the filter and just returns the water to the pool - so effectively no restrictions and you should feel more pressure at the return.
    This will allow you to at least eliminate the pipe from the pool to the pump

  6. Back To Top    #6
    Thanks for the advice. I will give these things a try and report back.
    22000 gallon, vinyl, 1.5HP Century Centurion Pump
    Hayward Sand Filter (no.20 silica sand)
    PoolVac Plus Automatic Cleaner

  7. Back To Top    #7

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    One other thing... with a crack in the basket. You may have a clogged impeller.
    Luv& Luk
    -Ted

    Having done construction and service for 4 pool companies in 4 states starting in 1988, what I know about pools could fill a couple of books - what I don't know could fill a couple of libraries :-D

    POOL SCHOOL, TF Testkits, Jason's Pool Calculator, CYA vs. cl chart, (Just a few DARNED handy links!)

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    duraleigh's Avatar
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    I really like the advice in this thread. It's common sense and should get your problem identified cheaply and quickly.

    Nice work, Jason, Ted and Matt.............You guys are all smarter than me but, remember, I'm much better looking!!
    Dave S. - Forum owner
    42k vinyl and concrete pool, 1.5hp pump, 140gpm filter
    TFTestkits , PoolMath , Pool School

  9. Back To Top    #9
    HAHA - Duraleigh - I wouldn't say that, there's been just as much advice given by you that was just as useful and helpful.
    We haven't even gotten to the root of this problem yet and we're already getting all sorts of Kudos!

    back to the topic - Waste - good catch - I read it wrong and took it for skimmer basket having a crack - yes - definitely check impeller for debris.
    Also, this debris could have pushed through into your multiport valve and clogged it, so you may have to remove the multiport and disassemble it to find out.
    Then there's teh other problem, once debris that large gets sucked into the pipes, if you backwash whilst having leaves in your pipes, they can push down into the standpipe and laterals effectively blocking the laterals up too, then when you go back to filter mode, hopefully, the leaves will reverse out and blow though to the return back to the pool, however, they may also be jammed in so bad that they are stuck and you'll need to take the entire filter appart....

  10. Back To Top    #10
    Just an update. I unscrewed the pressure gauge and let some water run out. This had no effect on the pressure. The flow pressure at the return feels the same at filter and recirculate settings. I can't say for sure but I think it feels like overall the return flow is less than what it used to be. However, everything seems to be running fine though. My Zodiac Barracuda G4 has excellent flow and seems to actually be cruising around much faster. The clear window on the pump barely has any air bubbles in it. So maybe I just need a new gauge because it still reads about 10 PSI less than normal.

    I still think it has something to do with the cracked basket because this started about a day after I noticed the crack. So now I guess the next step would be to check the impeller for debris but I'm not sure how to do that. Any advice?
    22000 gallon, vinyl, 1.5HP Century Centurion Pump
    Hayward Sand Filter (no.20 silica sand)
    PoolVac Plus Automatic Cleaner

  11. Back To Top    #11
    JasonLion's Avatar
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    To check the impeller you turn everything off, open up the pump lid, remove the pump strainer basket, and look or reach down below the basket for the impeller. Depending on the pump this can be very easy to quite tricky.
    19K gal, vinyl, 1/2 HP WhisperFlo pump, 200 sqft cartridge filter, AutoPilot Digital SWG, Dolphin Dynamic cleaning robot
    Creator of PoolMath and Pool Calculator. Other handy links: Support this site, TF Test Kits, Pool School

  12. Back To Top    #12
    spend 5 bucks on a new gauge - if it isn't the gauge, you'll need it eventually anyways....

  13. Back To Top    #13
    Problem Solved!

    So it turns out that the problem was with the impeller. I took out the basket and reached down into the pump and there was tons of leaves and things that were lodged into the impeller. I used a screwdriver to loosen everything up and it all came out. I replaced the cracked basket with a new one and the pressure is back up to its normal 15psi.

    Thanks to everyone for all the advice. I was very close to calling someone out to take a look at it. It only took 5 minutes to fix and probably would have cost me $100 or more if I called a pool guy.
    22000 gallon, vinyl, 1.5HP Century Centurion Pump
    Hayward Sand Filter (no.20 silica sand)
    PoolVac Plus Automatic Cleaner

  14. Back To Top    #14
    tagprod's Avatar
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    Quote Originally Posted by JasonLion
    The two most likely possibilities are, either the gauge is broken or the pipe from the skimmer to the pump is clogged. How is the water flow comming out of a return? If you still have good strong water flow then it is probably the gauge. To try and clear out the pipe you could get a drain king, hook that up to your garden hose, and get the drain king into the inlet pipe at the pump (you may need to remove the pump strainer basket to get full access). If there is something blocking the pipe that will usually blow it out.
    what's a drain king and where do you find it? I've noticed some lower pressure on my filter too. I know the gauge is OK as I just replaced it. The flow on the returns feels less than what I remember it being. The PSI used to be a steady 20 right after the cartridge was changed but it was at 10 when I checked today. I noticed the pump sounded louder than normal too. I took out the strainer basket and cleaned out some grass that was in there, but there wasn't much. I bled the cartidge filter after putting the pump lid back on and pressure did go up to about 14.
    Brian
    20K IG Gunite w/ raised 7ft spillover spa. 1.5 HP Hayward Northstar pump 425 sq ft Hayward cartridge filter, Colorlogic lights AquaRite SWG AquaLogic PS-8 control
    1hp pump for sheer descent

  15. Back To Top    #15
    JasonLion's Avatar
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    A Drain King is an attachement for a garden hose that you fit into the end of a pipe. Water pressure causes it to seal and pressurize the pipe, which hopefully pushes any clogs through the pipe to the other end.
    19K gal, vinyl, 1/2 HP WhisperFlo pump, 200 sqft cartridge filter, AutoPilot Digital SWG, Dolphin Dynamic cleaning robot
    Creator of PoolMath and Pool Calculator. Other handy links: Support this site, TF Test Kits, Pool School

  16. Back To Top    #16
    tagprod's Avatar
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    Quote Originally Posted by JasonLion
    A Drain King is an attachement for a garden hose that you fit into the end of a pipe. Water pressure causes it to seal and pressurize the pipe, which hopefully pushes any clogs through the pipe to the other end.
    how come pressure doesn't go up in this case?
    Brian
    20K IG Gunite w/ raised 7ft spillover spa. 1.5 HP Hayward Northstar pump 425 sq ft Hayward cartridge filter, Colorlogic lights AquaRite SWG AquaLogic PS-8 control
    1hp pump for sheer descent

  17. Back To Top    #17
    JasonLion's Avatar
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    You do this with the pump off and both ends of the pipe open. The pressure in the pipe goes up and hopefully the clog comes out. Then you remove the Drain King and reconnect everything and turn the pump back on.
    Attached Images Attached Images
    19K gal, vinyl, 1/2 HP WhisperFlo pump, 200 sqft cartridge filter, AutoPilot Digital SWG, Dolphin Dynamic cleaning robot
    Creator of PoolMath and Pool Calculator. Other handy links: Support this site, TF Test Kits, Pool School

  18. Back To Top    #18
    tagprod's Avatar
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    Quote Originally Posted by JasonLion
    You do this with the pump off and both ends of the pipe open. The pressure in the pipe goes up and hopefully the clog comes out. Then you remove the Drain King and reconnect everything and turn the pump back on.
    I meant wouldn't debris stuck in the return lines cause the pressure to go up?
    Brian
    20K IG Gunite w/ raised 7ft spillover spa. 1.5 HP Hayward Northstar pump 425 sq ft Hayward cartridge filter, Colorlogic lights AquaRite SWG AquaLogic PS-8 control
    1hp pump for sheer descent

  19. Back To Top    #19
    JasonLion's Avatar
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    Yes, debris stuck in the return lines would cause the pressure to go up. I was suggesting that they might want to use a drain king on the suction line to the skimmer. Debris in the pipe to the skimmer would cause the filter pressure to go down.
    19K gal, vinyl, 1/2 HP WhisperFlo pump, 200 sqft cartridge filter, AutoPilot Digital SWG, Dolphin Dynamic cleaning robot
    Creator of PoolMath and Pool Calculator. Other handy links: Support this site, TF Test Kits, Pool School

  20. Back To Top    #20
    tagprod's Avatar
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    Quote Originally Posted by JasonLion
    Yes, debris stuck in the return lines would cause the pressure to go up. I was suggesting that they might want to use a drain king on the suction line to the skimmer. Debris in the pipe to the skimmer would cause the filter pressure to go down.
    ah ha - maybe I should read a little closer before typing. Thanks.
    Brian
    20K IG Gunite w/ raised 7ft spillover spa. 1.5 HP Hayward Northstar pump 425 sq ft Hayward cartridge filter, Colorlogic lights AquaRite SWG AquaLogic PS-8 control
    1hp pump for sheer descent

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