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Thread: Shutting down and starting your pump

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    Shutting down and starting your pump

    OK, so like a big dummy noob, I got home yesterday and decided to backwash my sand filter and first turned off the pump without shutting any valves...

    So... When I started everything back up to backwash, I lost the prime. I do know (from the pool inspection done during the purchase of the house last month) that there is a problem with my suction lines "sucking air" and I need a bit of repair done there...

    BUT... After priming, and priming, and priming, and priming... My pump is STILL not pulling water. It will sometimes start filling up the bowl, but then everything goes to nothing... Maybe a drizzle of water coming through, but certainly not what it should be.

    So two questions...

    1. What is the PROPER way to shut off a pump in order to backwash the filter? What valves should be closed/open before shutting off the power and then the same for turning on the power?
    2. What am I doing wrong that is keeping me from priming my pump?

    I had this same problem last week and FINALLY got it going after about 20 attempts, but last night it just would NOT take off...

    Here's how I've been trying to prime:

    Skimmer valve and main drain valve closed.
    Pressure releif valve open.
    Main return open - secondary closed.
    Fill the pump bowl with water.
    Close pump bolw lid.
    Turn on pump.
    Open skimmer or main drain valve (usually skimmer) but NOT both.
    When only water is coming out, close relief valve.

    Stand back and watch the water flow through the bowl for a few seconds then die.

    My suction valves are about 40 ft from the source (ball type that will be replaced soon) and the skimmer is about 4 ft below them, so the main drain would be about 12 ft? Maybe my pump is not big enough? When it is running, it runs fine except for some air due to the afore mentioned system leaks.

    Side note: I'm learning a LOT from this site... VERY informative!!! You guys ROCK!!!!
    17 x 32 feet in-ground - 22,500 gallons - Vinyl liner
    Haywood sand filter (Model TBD) - Pump (TBD)
    Hot Spring spa
    Total noob...

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    Melt In The Sun's Avatar
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    Re: Shutting down and starting your pump

    I'd just open all the valves and see what happens.
    11,200 gal, Pebble-Tec; Tristar 2-speed 1hp - Swimclear 325 ft2 cart - SWG - A & A in-floor cleaner - Heat pump. For the poolside cooking, a Yoder Wichita and a Big Steel Keg!
    TF Test Kits -- PoolMath -- Pool School
    Make each day your masterpiece. - John Wooden

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    Mod Squad JohnT's Avatar
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    Re: Shutting down and starting your pump

    If your skimmer is 4ft below the pump, you may struggle to prime. If you shut off both inlet valves as soon as you shut the pump down, that should help hold water in them to make it easier to prime. With that kind of drop, you probably want a check valve at the pump inlet.
    TFP Moderator
    20K Gallon 20X36 Vinyl Inground
    Hayward S244T Sand Filter with 1HP Whisperflo Pump. Liquidator C-201 and Solar Heat

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    Re: Shutting down and starting your pump

    1. Fixing/finding your suction side air leak(s) will eliminate the problem.

    2. Meanwhile, there is really no point in closing both skimmer and main drain valves.....close one or the other when priming but not both.

    3. It sorta' sounds like your water level is not high enough in the pool and you are sucking air into the skimmer......raise your water level if that's the case. Pull from the main drain only to confirm that.
    Dave S.
    42k vinyl and concrete pool, 1.5hp pump, 140gpm filter
    TFTestkits , PoolMath , Pool School

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    Re: Shutting down and starting your pump

    I did try to prime from the main drain as well, with the same results.

    I'm "guess-timating" the drop. It could be only a couple of feet. I may laser it to be sure.

    Water level is halfway up the skimmer opening. My limited research makes me think this is sufficient. Is it?

    Quote Originally Posted by duraleigh
    Meanwhile, there is really no point in closing both skimmer and main drain valves.....close one or the other when priming but not both.
    So when I fill up the pump bowl, the excess drains back into the inlet pipe. If this valve is open, it continues to fill (I'm thinking it's just all going back to the pool.) If I understand you correctly, I should just fill to the bottom of the inlet and leave one valve open? I'll try that one for sure!

    Quote Originally Posted by JohnT
    With that kind of drop, you probably want a check valve at the pump inlet.
    I'm thinking that's a good idea for sure.

    Thanks ya'll!!

    With the temps we're having here now, this may be a moot point until next May...
    17 x 32 feet in-ground - 22,500 gallons - Vinyl liner
    Haywood sand filter (Model TBD) - Pump (TBD)
    Hot Spring spa
    Total noob...

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    Melt In The Sun's Avatar
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    Re: Shutting down and starting your pump

    Just a thought; are you lubing up the o-ring on the pump basket lid when you open it up? That's the most common place for an air leak, and if you've been opening and closing it a lot that's the first thing I'd check.
    11,200 gal, Pebble-Tec; Tristar 2-speed 1hp - Swimclear 325 ft2 cart - SWG - A & A in-floor cleaner - Heat pump. For the poolside cooking, a Yoder Wichita and a Big Steel Keg!
    TF Test Kits -- PoolMath -- Pool School
    Make each day your masterpiece. - John Wooden

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    Re: Shutting down and starting your pump

    Well, another couple of hours that I will never get back last night...

    I tried to seal all the connections from the intake pipe at the ground to the pump with butyl tape (temp fix, I know...), but still no luck...

    I checked the o-ring and it probably does need some lube, but not a drop in the house - not even vaseline... I'm not sure this is the issue because of the following:

    The first time I tried to prime it, I thought it was going to take off. It kept trickling water into the bowl for a minute or so, then started catching up. After a few seconds, it filled up and began pumping as it should. But then about 5 seconds later, it just "died" with nothing coming in through the intake. As I said, the water level in the pool is halfway up the skimmer, so I don't think that's it. I let it run for a couple more minutes, but nothing happened.

    Pump is a 1hp, not sure of the flow. Maybe the impeller has issues? But the funny part is that prior to Tuesday evening, it had been running and pumping fine for over 72 hours straight...

    Hopefully, my lovely bride knows someone with a lot of pool experience that may come over this evening to see if he can help. Maybe we'll get everything going just in time to close it..

    Still, any ideas are appreciated...
    17 x 32 feet in-ground - 22,500 gallons - Vinyl liner
    Haywood sand filter (Model TBD) - Pump (TBD)
    Hot Spring spa
    Total noob...

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    Richard320's Avatar
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    Re: Shutting down and starting your pump

    Hmmm...
    The first time I tried to prime it, I thought it was going to take off. It kept trickling water into the bowl for a minute or so, then started catching up. After a few seconds, it filled up and began pumping as it should. But then about 5 seconds later, it just "died" with nothing coming in through the intake. As I said, the water level in the pool is halfway up the skimmer, so I don't think that's it. I let it run for a couple more minutes, but nothing happened.
    Might be a sticking weir - the little flapper between the skimmer and the pool. It might be just starting to prime when it gets a shot of air and all is lost. You can move a lot of water with a pool pump, it wouldn't take but a split second to suck all the water out of the skimmer and the piping. No doubt you've witnessed the huge volume of water you can move when you backwash!

    I'd enlist a second set of hands. Close all the suction valves, fill the strainer basket with a hose, secure it. Then have the helper throw the switch as you open one of the valves. And if it starts pumping, open the air bleed right away until it starts spitting.
    16K freeform gunite with spa; Pentair 4000 DE filter; Century Whisperflow 1 HP; Pentair Minimax heater.
    Troublefree does not mean Maintenancefree. It's like brushing your teeth: You can spend a couple minutes a day and pennies a week or go to the dentist once a year and spend several thousand dollars.
    A pool is like a pet - you have to feed it every day, even the days you don't want to play with it!

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    Re: Shutting down and starting your pump

    The first time I tried to prime it, I thought it was going to take off. It kept trickling water into the bowl for a minute or so, then started catching up. After a few seconds, it filled up and began pumping as it should. But then about 5 seconds later, it just "died" with nothing coming in through the intake.
    Hmmm. Well, that description seems to indicate that, as it begins to prime, the increased flow (and resultant negative pressure inside the pump basket) is suddenly allowing something to "let go" and allow air to enter the system. Again, it points to the skimmer but there could be other causes, I guess.

    As Richard says, make sure you have someone observing the skimmer when the pump is priming to definitively eliminate it as the cause. It only takes about 1/2 a second for the skimmer throat to gulp air and then be covered back with water once prime is broken.
    Dave S.
    42k vinyl and concrete pool, 1.5hp pump, 140gpm filter
    TFTestkits , PoolMath , Pool School

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    Re: Shutting down and starting your pump

    UPDATE!!!

    Richard and duraleigh are geniuses!!!

    Got home and tried one more time to prime the pump without success... THEN....

    Took my garden hose, and stuck it through the weir from the pool side to help hold it open and making sure there was water going continuously into the skimmer. Filled the intake bowl with water, turned on the pump, and VOILA!!!! SUCCESS!!!!

    Thanks guys...

    On another note, I had a guy who spent 16 years in the pool business before becoming disabled come by to give me some pointers and help. He said to take the weir off, take some sandpaper or scotchbrite, and work on the edges to help the sticking weir.

    He also pointed out some leaks (I knew this, but he found them very quickly) at both intakes - main drain and skimmer. He's going to bring his son over and re-plumb it for me soon. Should take care of a LOT of problems.
    17 x 32 feet in-ground - 22,500 gallons - Vinyl liner
    Haywood sand filter (Model TBD) - Pump (TBD)
    Hot Spring spa
    Total noob...

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    Re: Shutting down and starting your pump

    Richard and duraleigh are geniuses!!!
    Very nice work on your part, AFG. Richard is the genius.....I am just a bloviaitng pretty face!
    Dave S.
    42k vinyl and concrete pool, 1.5hp pump, 140gpm filter
    TFTestkits , PoolMath , Pool School

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    Richard320's Avatar
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    Re: Shutting down and starting your pump

    Quote Originally Posted by ArkieFlyGuy
    UPDATE!!!

    Richard and duraleigh are geniuses!!!
    Well, yeah....
    On another note, I had a guy who spent 16 years in the pool business before becoming disabled come by to give me some pointers and help. He said to take the weir off, take some sandpaper or scotchbrite, and work on the edges to help the sticking weir.
    Have him look at the pictures in this thread and tell us what brand filter that is.
    16K freeform gunite with spa; Pentair 4000 DE filter; Century Whisperflow 1 HP; Pentair Minimax heater.
    Troublefree does not mean Maintenancefree. It's like brushing your teeth: You can spend a couple minutes a day and pennies a week or go to the dentist once a year and spend several thousand dollars.
    A pool is like a pet - you have to feed it every day, even the days you don't want to play with it!

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