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Thread: no prime

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    no prime

    hey guys, ive got an inground pool, and as i fill the suction line to the skimmer, thru the pump, it fills the pool w/ water instead of coming back and overflowing the pump to get a prime. i am new at pool ownership, this is my first season ever. i caught the tail end last september when i bought my first home, and quickly had to close, but when i filled thru the pump to get prime it only took a few seconds to overflow, now it fills the pool instead of overflowing the pump for a prime. i only have one skimmer and one main drain, oh and the same goes for the main drain if i shut the skimmer valve and fill the main drain it will just fill the pool instead of filling up and overflowing the pump. any ideas!!!!
    20x40 IG vinyl, grecian style, 32.5k gal, hayward ec75a perflex d.e. hayward super pump 1 hp 80 gpm, 8 hr 38k gal turnaround

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    JasonLion's Avatar
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    Re: no prime

    Welcome to TFP!

    You don't need to completely fill the pump strainer basket with water. It should still have a fair bit of water in it, even after some of the water runs back into the pool. Even not completely full, the pump should still prime.

    It is easier to prime the pump if you close either the skimmer or the main drain valves (but not both). Once you have primed, slowly open the other valve to get the other line primed.
    19K gal, vinyl, 1/2 HP WhisperFlo pump, 200 sqft cartridge filter, AutoPilot Digital SWG, Dolphin Dynamic cleaning robot
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    Re: no prime

    i forgot to mention the pool is 2 maybe 3 feet higher then the pool, and i do have the main shut off as i am filling the line to the skimmer, and i tried all day to get the pump started but no dice.
    20x40 IG vinyl, grecian style, 32.5k gal, hayward ec75a perflex d.e. hayward super pump 1 hp 80 gpm, 8 hr 38k gal turnaround

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    Mod Squad Bama Rambler's Avatar
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    Re: no prime

    How long are you letting the pump run each time you're trying to prime it? The first opening it sometimes takes a while for the pump to prime because everything is empty. You do have the return valve open, right? Just making sure. also if you have an air purge fitting on your filter open it.

    Also, please tell us what equipment you have. Pump, filter, etc.
    Dave J. TFP Moderator
    24' x 52" Round AGP. 2hp/¼hp SPL Power-Flo 2-speed pump. 200sqft Waterway Cartridge Filter. 45MHP2(3GPD) Stenner Peristaltic Pump
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    Re: no prime

    ive got a 20x40 grecian 3' to 8' w/ a hayward super pump 1 hp, and hayward ec75a perflex d.e. filter. the thing that gets me is that it used to fill up and overflow the pump when i added water thru the pump housing and now it does not, the water just goes into the pool and does not come back to the pump filling the line like it used to.
    20x40 IG vinyl, grecian style, 32.5k gal, hayward ec75a perflex d.e. hayward super pump 1 hp 80 gpm, 8 hr 38k gal turnaround

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    Mod Squad Bama Rambler's Avatar
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    Re: no prime

    Is there a check valve in the line? If so then it's possible that it's stuck open allowing water to flow backwards into the pool. That would explain the fact that it used to fill up and now it won't.
    Dave J. TFP Moderator
    24' x 52" Round AGP. 2hp/¼hp SPL Power-Flo 2-speed pump. 200sqft Waterway Cartridge Filter. 45MHP2(3GPD) Stenner Peristaltic Pump
    Pool School ----- Pool Math ----- TF-Test Kit

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    Re: no prime

    i dont know, but if there is, its buried, and not exposed, i re routed all my lines, and added all new jandy diverter valves, and ran a bypass and raised the whole unit another 6" or so, but that still doesnt explain why the water just flows back to the pool.
    20x40 IG vinyl, grecian style, 32.5k gal, hayward ec75a perflex d.e. hayward super pump 1 hp 80 gpm, 8 hr 38k gal turnaround

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    mas985's Avatar
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    Re: no prime

    Post a picture of your equipment pad and maybe we can figure it out. Normally, with a pad that high, a check valve is installed on suction side of the pump. This allows you to fill the pump basket without it flowing back out. As Bama mentioned, if it failed, then water would run out. A failed check valve might restrict the flow as well making it even harder to prime.
    Mark
    Hydraulics 101; Pump Ed 101; Pump and Pool Spreadsheets; Pump Run Time Study; DIY Acid Dosing; DIY Cover Roller
    18'x36' 20k plaster, 1/2 HP 2sp pump, Aqualogic PS8 SWCG, 420 sq-ft Cartridge, Solar, 6 jet spa, 1 HP jet pump, 400k BTU NG Heater, ThePoolCleaner

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    Re: no prime

    where would the check valve be? cause if its exposed and close to the pump it would defeat the purpose, you would then only have a few inches of water in the line, and nothing behind it but air, so when you start the pump, you would only suck the water up to check valve, and then once it opens the valve, it will suck air thats between the check valve and the skimmer and lose prime!

    unless the check valve is installed in or under the skimmer then the whole line would be full at all times! is that crazy cause thats what my logic is telling me, but my logic is also questionable LOL
    20x40 IG vinyl, grecian style, 32.5k gal, hayward ec75a perflex d.e. hayward super pump 1 hp 80 gpm, 8 hr 38k gal turnaround

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    mas985's Avatar
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    Re: no prime

    You don't need to have the entire pipe filled with water to prime a pump. A pump will generally prime with half a basket full of water. However, a check valve allows you to fill the entire pump basket so in effect you have about twice the water to prime the pump than without it. This is usually enough to get the pump primed even under the most difficult circumstances.
    Mark
    Hydraulics 101; Pump Ed 101; Pump and Pool Spreadsheets; Pump Run Time Study; DIY Acid Dosing; DIY Cover Roller
    18'x36' 20k plaster, 1/2 HP 2sp pump, Aqualogic PS8 SWCG, 420 sq-ft Cartridge, Solar, 6 jet spa, 1 HP jet pump, 400k BTU NG Heater, ThePoolCleaner

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    Re: no prime

    yeah but the pump doesnt have to work hard w/ full lines, less stress and less wear and tear, equals longer life, and smoother operation and again the check valve thing is just going make the pump work harder as soon as it opens and starts sucking air. espescialy since my lines are 30' away and 2' uphill thats alot of air
    20x40 IG vinyl, grecian style, 32.5k gal, hayward ec75a perflex d.e. hayward super pump 1 hp 80 gpm, 8 hr 38k gal turnaround

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    mas985's Avatar
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    Re: no prime

    Pumps are made to prime up to 8-10' above the water line so 2' is no problem at all. One thing to keep in mind is that you only prime occasionally. Once a pump is primed, it should not lose prime unless air enters the plumbing from somewhere. The act of priming would be damaging to a pump if it operated that way all the time but if it is only done a few times a month, it really isn't going to reduce the life of the pump.

    Besides, you don't have a choice. With the pump above the pool, it is impossible to fill the lines with water except by the pump priming. But the check valve will prevent the water from draining out of the suction pipe so next time, priming won't require removal of the air.
    Mark
    Hydraulics 101; Pump Ed 101; Pump and Pool Spreadsheets; Pump Run Time Study; DIY Acid Dosing; DIY Cover Roller
    18'x36' 20k plaster, 1/2 HP 2sp pump, Aqualogic PS8 SWCG, 420 sq-ft Cartridge, Solar, 6 jet spa, 1 HP jet pump, 400k BTU NG Heater, ThePoolCleaner

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    Re: no prime

    "Pumps are made to prime up to 8-10' above the water line so 2' is no problem at all."
    thats a hugh releif, because i raised my pad when i ran all the new lines, like a newbie i had no idea it had effect on the pump at the time until i finished the job and started to research pool stuff and saw peolple saying things like that was to high. so much so that its one of the reasons why i started this post. so i feel rest assured on this now that its not to high. one less worry.
    20x40 IG vinyl, grecian style, 32.5k gal, hayward ec75a perflex d.e. hayward super pump 1 hp 80 gpm, 8 hr 38k gal turnaround

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    Re: no prime

    i got the pump started after i realized that the plug was still in the return jet in the pool DUH!!! CAN YOU TELL IM A NEWB? my pool is still covered and i just wanted to circulate, to test all my new plumbing to check for leaks and stuff w/ out opening the pool, and i totally forgot about that plug in the jet so i unscrewed it and she got a prime. but w/ the bypass i ran, it pulls the water very fast thru the skimmer, and loses prime, even at the appropriate water height, it pulls it as if it the water were low.
    20x40 IG vinyl, grecian style, 32.5k gal, hayward ec75a perflex d.e. hayward super pump 1 hp 80 gpm, 8 hr 38k gal turnaround

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