Pump won't fully prime

Hello, first I want to say thank you for such a great community on this site!

I'm new to pools and recently moved into a house with a 6 or 7 year old vinyl pool. The company I went with to open the pool told me they couldnt get a full prime in the pump but that it was "good enough". This past weekend my neighbour heard my pump constantly priming and unpriming and shut it off for me. No idea how long it was doing that. When i checked it out, it looked like as soon as the pump would near prime, it would have sucked theskimmer dry and start pulling in air. The water was just under .5 of the skimmer face plate, so i guess it needs to be more like .75 for normal running.

Now, no matter what I do, I cannot even achieve the same level of priming that I had before. There is a lot of air in the pot and I can still see the top of the inlet; however filter pressure is still good at 15 psi.

At first, I had the "good enough" prime with the skimmer fully open and main drain at half. The we realized the second skimmer hole was for the vac and had that at full as well. Now I have all 3 at full and cannot fully prime.

I've got a jandy 1hp stealth pump running what the pool guy says is 1.5" piping underground (2" above ground).

Yesterday while in the water I couldn't feel any suction on either of my 2 main drains, but I hear that's the way it's supposed to be. My skimmer has 2 holes, one for skimmer and the other for vac.

While playing around, I got the pump to prime as much as possible then shut the 2 skimmer lines to make sure I was getting water from the main drains, but it wasn't as much as just a single skimmer hole.

I've tried releasing the pressure valve on my jandy sand filter as well as tying plastic bags around joints to try to stop any air leaks. I've put o-ring lube on the pump pot gasket, and checked all unions to make sure they are tight. Nothing seems to get the pump to fully prime. I've ordered a new pot gasket as the current one is cracked

Is there anything I'm missing?
 
Welcome! :wave:

Sounds to me like the water level is too low. But whatever, it's an air leak.

[center:3n2zj5jp]Round up the usual suspects: low water level, stuck weir in the skimmer, loose drain plugs on the
pump, poor seal on the pump strainer basket, and leaks at the fittings, especially any couplings.
[youtube:3n2zj5jp]vtSmfws0_To[/youtube:3n2zj5jp][/center:3n2zj5jp]
 
Richard

Thanks for the quick response.

The water level is about 2/3 up the skimmer opening (higher than i used to keep it) and the weir is still bobbing freely. Theres now plenty of water in the skimmer but the pump seems to not get enough!

Im hoping the new pump strainer gasket is the fix.

I can't seem to find anything loose or leaking and all are tight.

I have noticed that it sounds like I can hear water trickling through the filter. I have back washed just to be safe but no difference.

Ill shut off the pump for the night and try again after work tomorrow

Thanks!

My fear is a clogged line under ground.
 
I had something very similar. I had to buy a new lid for the pump, a strainer gasket did not work.

Bought a new lid (more expensive than I thought) for that pump, bought some pool lube, changed lid, lubed up the lid, restarted pump and all problems went away.......no 'water splash' from the lid when turning off after installing new lid and lube. That is how I tell if the lid seal is gone, if water escapes, it isn't air tight.......
 
Update: new pump filter gasket made no difference :(

When the pump gets near primed there is no surging and the filter has the normal (to me) 15psi. I tried playing around with valves. Running the pump off of just the vac and main drains it almost got to the level of prime im now stuck with. Then, when I cracked open the other skimmer line the pump almost lost all water. This other line is supposed to be the 2" off the skimmer, but it appears the company that installed the pool only ran 1.5". The only time I hear any hissing is when closing off this other skimmer line. Both other valves don't make any sound.

I also tried wrapping the lid and all joints as best as I could with plastic wrap to see if there is any other air leaks and again there was no difference. When I shut off the pump, there is splash back, but no water leaks that I can find. The only leak I can see in the entire system is somewhere on the filter. Nothing major, but it's on the pressure side so I don't think it's causing my air leak.

Tried running with the filter on recirculate and the pump didn't even reach the near prime level. It sure of I waited long enough.

Could I have a leak or blockage under ground?

Is there anything to test or try?

Thanks for any and all help!
 
If you have an underground blockage, you can clear the line. Google "how to blow skimmer line" and you will get lots of instruction. I have had a lot of suction problems and it was always one of the basics as outline earlier by Richard320 and the only additional procedure I would add to that is to make sure you fill up the pump with water before you screw the lid on and attempt to prime.
Just because I had so much trouble with it, make triple sure that the weir door is functioning properly. Good luck, I am sure you will figure it out.
 

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True enough!

I tried the tennis ball trick in the skimmer. When it first gets sucked down, it stays for half a second and pops back up and I can feel the release of air that pushed it up. If I push it back down it stays and is fairly hard to pull back out. Seems like plenty of suction.

Going to get to home depot tomorrow and try the drain king from the pump backward to each return line one by one.

I wonder if my pool guy was right, the 2" puimp can't ever get enough water from 1.5" lines. Doesn't make sense as I've got 3 1.5" lines wide open and it used to be closer to being primed.

Thanks again for all the help and suggestions. I'm sure this will be sorted out short of getting a 2" flex line and running it from the pump into the pool to rule out all existing plumbing!
 
Update....

So I've tried even more randomness! Last night Tried soapy water to see if any bubbles get sucked in, failed. Tonight, we tried electrical taping all joints, didn't see any changes. However, the wife said to try recirculate, and after running about 5 mins to start pumping water and surging a bunch of times, the pump started running much closer to a full prime! Filter showed 10psi. When we shut it off, there was no back splash and the pump kept most water. Restarted in filter mode and it was pumping immediately, but with less of a prime then when under recirculate. Filter showed 15psi.

Could this mean an issue with my filter?
 
A couple more places to check for air leaks, the drain plug on the pump skimmer pot- make sure it is tight, and where the multi-port valve connects to the filter. You can use the soapy water or drizzle a thin stream of fresh water on all the areas where the pieces meet. You can also test the joints in the exposed plumbing this way.
 
Thanks everyone for the help. Unfortunately no closer I don't think.

I think I isolated a part of the issue, one valve sound like it sucks air unless fully open or closed, but even with that resolved the pump pot still has air in it.

Tried again the recirc setting, this time a trickle of water and air was coming out of the waste port, but the pump still got closer to prime. Did a quick backwash and set it back to filter, but some water was still coming out of the waste port. Reset it again to filter and all seems ok, except for the air in the pump.

Could it be my filter all this time?

I'm thinking that since the equipment is all 7 years old and this is my first season with the pool to just leave it and replace pump and filter when I got the cash...I fear that won't fix the problem, and just make it that much more expensive.
 
Every time I've had a problem like this it's been something in the pump basket assembly.

First time, I hadn't attached the pump basket to the skimmer line tightly enough. Second time, I had kinked the rubber o-ring.

Third time the pump basket gasket thing was folded over and sticking out of the cover.
 
weird_tolkienish_f said:
Every time I've had a problem like this it's been something in the pump basket assembly.

First time, I hadn't attached the pump basket to the skimmer line tightly enough. Second time, I had kinked the rubber o-ring.

Third time the pump basket gasket thing was folded over and sticking out of the cover.

What are you referring to as the "pump basket gasket thing"? I'm going to try removing all the piping from the pump to the vales and re-tapping and lubing the gaskets

Thanks!
 

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