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Thread: Pump not pulling water - help!

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    Pump not pulling water - help!

    Hi, have a pumping problem and no idea how to fix it!

    We moved into our lovely new house two months ago and all with the pool has been going swimmingly, which was good news because we are pool newbies and decided to take care of the pool ourselves, being that we're on a budget.

    A couple of weeks ago, I noticed that the pump was losing prime (I think) because on start-up a huge amount of air was violently erupting from the returns and the Polaris cleaner. However, this gradually ceased over a couple of minutes and pumping continued absolutely fine. (I notice that next-door's pool does the same thing although not quite so badly. So maybe it's normal?). I read through the forums, and decided to check the pump's O-ring as the port of first call in case there was an air-leak here. That's when we realised that the pump skimmer basket was quite full of debris, so we cleaned it all up, including the O-ring and the lid, re-lubed it and the priming problem definitely improved, although there is still some bubbling on start-up for 20 seconds or so. There is also a mysterious 'gurgling' coming from the filter unit several hours after switch-off with a very slight amount of water at the end of the filter unit effluent pipe (literally, a drop or so) which it did then and continues to do now.

    Given the amount of debris in the pump basket, I figured that we should probably also backwash the DE filter seeing as we'd been here for two months and using the pool. I had been keeping a check on the filter pressure (probably the only thing I'd been doing right) and it had finally increased from 30psi to 38psi, so it was definitely due.

    Backwashing went well, except that I didn't read the filter startup instructions properly and we switched the pump back on before we'd bled the air from the filter. I'd already plopped new DE into the pool skimmer basket and wondered why it wasn't going anywhere. We released the air, started the pump back up, and hey presto off it went merrily doing it's pumping job, the DE got sucked down the pipes and everything seemed to be running properly.

    A few days later, I discovered that the pump isn't pulling water through the pool skimmer basket again, although there is some water coming out of the return jets so it must be pulling from the main drain at least (?). The polaris just bobs around because presumably there isn't enough water coming to it to push it around the pool properly. Yesterday, husband repeatedly bled the air from the filter again and eventually the pump starting pulling water again. This morning, on startup, it's stopped pulling water through the skimmer again. So I've switched it off. (Too many horror warnings on the pump instructions about catching fire, exploding, etc etc. for my liking)

    SO, what is happening?? The lack of pumping action only started after backwashing the filter! Is there a pesky air bubble trapped somewhere in the system, and how do we get rid of it? Or, is air continually leaking into the filter unit, but where and how, and what do I do about it? And has the mysterious filter unit gurgling got anything to do with it?

    Help, and thanks!!
    Vicki
    12' x 20' kidney-shaped inground pool; one skimmer basket, 3 return jets.

    Purex Triton 'WhisperFlo' pump, model WFE-6, 1.5HP
    Purex Triton 2000 Series , model SMBW2072 (DE filter)
    Polaris 360 cleaner

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    Mod Squad JohnT's Avatar
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    Re: Pump not pulling water - help!

    Welcome to TFP, Vicki!

    Normally an air bubble would make things noisy, but probably won't stop your flow.

    A couple of easy things to check:

    Try setting your filter to recirculate (if your valve has that position). This will remove the filter from the system, running on just the pump.

    Check that the pool water level is at the mark on the skimmer face, and that the skimmer weir can move freely.

    Check any valves or unions in the suction lines for tightness.

    Check your pump winterizing plugs for tightness.

    Look for small drips of water while the pump is off, or small spurts of water right as you shut the pump off.
    TFP Moderator
    20K Gallon 20X36 Vinyl Inground
    Hayward S244T Sand Filter with 1HP Whisperflo Pump. Liquidator C-201 and Solar Heat

  3. Back To Top    #3

    Pump not pulling water - help!

    Can I jump in with a question? I switched mine to recirculate and wowsa! - what a difference that makes. So how can I get it to filter like that?
    Terre Haute, IN
    18 X 48 Intex Ultra-Frame AG
    Intex Saltwater Generator/sand filtration system

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    Richard320's Avatar
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    Re: Pump not pulling water - help!

    Quote Originally Posted by jennpleez
    Can I jump in with a question? I switched mine to recirculate and wowsa! - what a difference that makes. So how can I get it to filter like that?
    Clean your filter.
    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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    Richard320's Avatar
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    Re: Pump not pulling water - help!

    vickiarmstrong: check the water level in your skimmers. You lost a bunch when you backwashed, so it could be too low. Also check that the weir (the flapper) isn't stuck on your skimmer. Either one will allow your pump to suck air.

    You didn't possibly overload the filter with DE, did you? Unless you tore it all down and washed things, you should only put 80% of what they say in. Because at least 20% will stay stuck to things. Maybe even more. Here's a picture of my filter after the prescribed 2 minute backwash:
    [center:30vumsw3][/center:30vumsw3]

    Finally, you might have a clump of DE blocking the pipes. I'd just cram a garden hose down in the skimmer pipe and hold a rag over things to help seal it when the pump is running. That's easy to do when you're already poking around in there checked the water level and the weir.
    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!

  6. Back To Top    #6

    Re: Pump not pulling water - help!

    Thanks for the suggestions!

    The water level is good and the weir moves freely. I only added 4lb of the prescribed 4.8lb DE, so hopefully we did actually remove most of the old stuff and I didn't overload it. There are only 'run' and 'backwash' options on the filter, nothing to bypass the unit. I still need to check all the joints but I've got no idea what winterising plugs are! (I'm in Southern California so the pool will stay 'open' all winter, although I'm not planning on swimming in it!)

    I am having to bleed the air from the air filter every time I switch the pump on, and then it operates fine for the rest of the cycle, so I think that it's air in the system that seems to be the problem. Yesterday I noticed that water was continually dripping from the air filter bleed valve during pump operation. I wonder whether there is a leak somewhere in the filter unit that is letting air in overnight when the pump is switched off. Am I going to have to dismantle the filter unit and check O-rings and valves and things? There has been that strange gurgling noise from the filter unit and a tiny leak from the effluent pipe. The sound of water coming out and air leaching in? The mystery continues...
    12' x 20' kidney-shaped inground pool; one skimmer basket, 3 return jets.

    Purex Triton 'WhisperFlo' pump, model WFE-6, 1.5HP
    Purex Triton 2000 Series , model SMBW2072 (DE filter)
    Polaris 360 cleaner

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    elwood58's Avatar
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    Re: Pump not pulling water - help!

    Sounds like your filter is filling with air during the off cycle. Time to check and lube all o-rings, and make sure the bleed valve is closing all the way.
    19204 Gallon L Shape with a 10X10 2nd Step Baja Ledge. Intellichlor IC-40, IntellipH, Cartridge Filter, Pentair Heater/Chiller (Heat Pump). Tons of Deck with Deck Jets. Construction Complete 6/5/17.

    "If you don't measure it, you can't manage it!"

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