Pump losing prime

Rodex

Active member
Jun 2, 2019
33
Mansfield, TX
The past couple mornings we noticed the pump is full of air when it starts up. We recently changed the DE filter grid. The skimmer weir door is a universal replacement and if the pool level is a bit low it can cause some air, so I’m starting off with simply filling up the pool a bit.

The pump is a Jandy self-priming, so when it’s full of air it will eventually prime itself but I have understood that it’s not an ideal thing to do and there still needs to be some water in the lines for the self priming to work. We are going to be out of town soon so I would hate for the pump to break while we are gone. I’m also concerned about messing up the filter grids we just replaced, that would be annoying.

Anything in particular I should look for if adding water doesn’t work? I was thinking that maybe the Jandy pump itself needs new gaskets or something.
 

mknauss

Mod Squad
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May 3, 2014
21,223
Laughlin, NV
Is there air in the returns when the pump is running?

If the water is draining from the system with the pump off, but no air in the returns after the pump is primed and running, check your filter. It could be allowing the system to drain when the pump is off, but not show a leak with the pump on. With the system running normally, turn the pump off and listen at the equipment pad.
 

mknauss

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May 3, 2014
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Laughlin, NV
If it drains to the point the pump is dry, that means the filter is draining too most likely.

Is the pump remaining full of water?
 

Rodex

Active member
Jun 2, 2019
33
Mansfield, TX
Couple other observations since we have been taking a detailed look at it:
  • One of the return jets isn’t pushing water out but we are pretty sure this one has never functioned
  • My wife pointed out that one of the other jets could have a bit of air - I just thought it was turbulent flow and making little bubbles on the surface but I took a closer look and it does look like it’s aerating a bit
  • The pipe from the pump to the filter seems to have a small leak, more obvious when it’s running though
 

duraleigh

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Apr 1, 2007
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  • The pipe from the pump to the filter seems to have a small leak, more obvious when it’s running though.
    That pipe is pressurized (pump running) so, when you stop the pump, that leak allows air into the system and drains your pump and filter. Fix that leak and your pump will likely stop draining. I don't think the very small suction side leak is your issue,
 

Rodex

Active member
Jun 2, 2019
33
Mansfield, TX
Suction side leak. But fix the other leak too.
Had a maintenance guy out and over the past couple of weeks he has been chasing down the source. He fixed the PVC leak, changed the primary valve, replaced the top of what I think is a check valve, replaced the inlet gaskets on the pump, and replaced the “record player” top of the pump. It doesn’t seem to be losing prime anymore, which is good news! However, bubbles still seem to be sporadically coming out of the jets although not nearly as bad as they were. I can see bubbles pop up on the surface of the water and it’s visible coming out of the jets per the pic below. Is it normal to have a little?

113302
 

mknauss

Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
21,223
Laughlin, NV
Take a look around your suction side. You are still pulling in air. Does the pump basket stay full of water?
 

Rodex

Active member
Jun 2, 2019
33
Mansfield, TX
Sorry if I misunderstood, do you mean will it lose water over time or is there any air bubble at all in the pump basket? I’ll have to check again now that all these changes have occurred but I’ve always seen a bit of air trapped at at the top.