Trouble keeping System primed

ajw22

Gold Supporter
TFP Guide
Jul 21, 2013
7,807
Northern NJ
Your pump is priming fine. It gets water flowing. You have a suction side air leak sucking air in.

Likely from your pump basket top. I don't think you have it securely closed. I need to give mine a rap with a mallet. Check the O ring on it. You use POOL LUBE on the O ring?

 

duraleigh

Admin
Mod Squad
TFP Expert
Platinum Supporter
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In The Industry
Apr 1, 2007
32,351
Sebring, Florida
It is certainly a suction side air leak but please don't whack it with a mallet. That seal is made to seal itself and, if the o-ring is not damaged or worn, will typically seal itself if you simply hand tighten it.

That said, it is the most common place for a leak so take the lid off and examine the o-ring carefully. If it fits properly and feels correct when you turn the lid, it is probably fine.

There is an article HERE that may shed some light. Once you find the source of the leak (remember, it is ONLY somewhere between the skimmer(s) and the pump) it is normally and easy fix.
 

matt.burba

Active member
Aug 14, 2015
40
Okemos, MI
I am walking through the Suction Side troubleshooting methodically.

1) O-ring on the pump basket lid. I inspected, re-applied Magic Lube, and stopped locking with a hammer. Doesn't seem to be the problem.
2) Drain plug at the bottom of the basket. Pulled out, inspected, applied Magic Lube and some teflon tape. Also doesn't seem to be the problem.

Tried to start the pump again, in SPA mode (to and from Spa, which is closer than pool skimmer and generally has better luck), and voila it started to run. Let it run for a few minutes, then stopped and set it to Pool mode. It immediately emptied the basket and didn't draw any water in. Tried to prime by opening the basket and filling with water, twice, with no luck. Went back to SPA mode and it won't draw water there either.

Water level in SPA is as high as it can get. Water level in pool is about halfway up the skimmer opening.
 

matt.burba

Active member
Aug 14, 2015
40
Okemos, MI
The next area to try is the PVC fittings into the pump, and this makes me very nervous. I'm going to post pictures to see if y'all can give me some advice.
 

ajw22

Gold Supporter
TFP Guide
Jul 21, 2013
7,807
Northern NJ
Post pics of the suction side of your pump so we can follow along.

Wrap saran wrap around pipe joints that may be leaking. They will get sucked in and seal the leak.
 

matt.burba

Active member
Aug 14, 2015
40
Okemos, MI
First pics are of the drain plug for the basket and o-ring for the basket. As I mentioned, both look fine.

Next two pics are the PVC connections that lead into pump. I'm assuming I have a leak there somewhere?

Trying to post the pic with Saran wrap applied but server is not letting me.
 

matt.burba

Active member
Aug 14, 2015
40
Okemos, MI
I have been running this pump 24/7 for three weeks as I've been doing a SLAM. The issue seems to be when the pump sits for a period of time... Instead of restarting, it will run the pump dry, just won't pull any water.

It was happening intermittently at the end of last season, but I usually could get it going by refilling the water basket and restarting, though sometimes it would take 5-10 tries.

Any thoughts of things I should check to test/isolate the problem?
 

mikegmi2

Well-known member
Jun 7, 2019
57
Michigan
What about that gray little plug in the black fitting going directly into your pump basket? Have you tried putting Teflon tape and lube on that?

Your PVC connections all look good from the pics, but air leaks are tiny little things that are very hard to find (in my experience). I fixed an air leak I had, but never pinpointed exactly where the problem was...so now I am back to square one troubleshooting again.

I don't see any unions in your pics, but if you have unions on the suction side take them apart and inspect the o rings inside. Make sure no cracks or wear and tear, lube them up good, and tighten unions back together.

A good tool for loosening unions is an oil filter wrench if you don't have a rubber union wrench. A lot of people prefer the oil filter wrenches actually, which is what I use.
 

ajw22

Gold Supporter
TFP Guide
Jul 21, 2013
7,807
Northern NJ
A bit wider angle view would let us get the big picture.

You said the pump worked fine in spa mode and sucks air in pool mode. Your pics don't let me see the valve or which pipes are used in spa vs pool mode.
 

matt.burba

Active member
Aug 14, 2015
40
Okemos, MI
What about that gray little plug in the black fitting going directly into your pump basket? Have you tried putting Teflon tape and lube on that?

Your PVC connections all look good from the pics, but air leaks are tiny little things that are very hard to find (in my experience). I fixed an air leak I had, but never pinpointed exactly where the problem was...so now I am back to square one troubleshooting again.

I don't see any unions in your pics, but if you have unions on the suction side take them apart and inspect the o rings inside. Make sure no cracks or wear and tear, lube them up good, and tighten unions back together.

A good tool for loosening unions is an oil filter wrench if you don't have a rubber union wrench. A lot of people prefer the oil filter wrenches actually, which is what I use.
That grey little plug is where my old Sense and Dispense system put water back into the system. I've covered it with Saran wrap too for the short term