Priming a Pentair SuperFlo Variable Speed Pump

SCRealtor

Member
May 16, 2019
5
Orange County, CA
I'm trying to help my parents lately with their pool equipment. It used to be one of my chores when I was in high school in the 70s. The pool was built in 1971. I've been trying to familiarize myself with their old equipment. I know just enough about pools to be dangerous.

Last year, I replaced their pump with a Pentair SuperFlo variable speed pump. It has worked fine. This past week, though, I've had difficulty priming the pump after cleaning out the filter basket. When I've tried to fill the pump with water prior to replacing the lid and starting the motor, I can't fill it. Rather than overflowing as it has in the past and as it does on the Pentair pump at my house, the water seems to be draining out of the pump. The result is that I can quite a bit of air through the transparent lid.

Any thoughts?
 

Texas Splash

Mod Squad
TFP Expert
LifeTime Supporter
Welcome to TFP! :wave: Typically when you see air under the clear lid, it's a result of a suction side air leak. Air getting pulled-in. The #1 culprit is usually the clear lid's O-ring. Was it lubed with a pool silicone? What about the drain plug(s)? If so, then work your way backwards from the pump intake to the pool skimmer. Anything & anywhere along that suction line.

Also see Suction Side Air Leaks - Trouble Free Pool. Let us know how things go.
 

SCRealtor

Member
May 16, 2019
5
Orange County, CA
Thanks for the reply, but the concern I have is that I can't fill, or overfill, the area where the basket/filter is located; it seems to drain. In the past I have been able to overflow the reservoir (as I do on the pump on my own pool), but this one now seems to be draining when I try to fill it. The priming already begins with a significant amount of air under the lid. I don't see the amount of air increasing once the pumped is turned on.
 

Texas Splash

Mod Squad
TFP Expert
LifeTime Supporter
If the drain plugs are present, then let's back-up and go back to basics that would inhibit prime:
- Air leak somewhere allowing water to equalize and perhaps flow backwards to the pool; For this one we may need to know more about your parent's pooland equipment. But check any air relief valve on the filter and any other potential places where air can enter the plumbing. Look for spurts of water when the system is turned-off. A pic may help.
- Water level okay into mouth of skimmer
- Weir door operating okay
 

SCRealtor

Member
May 16, 2019
5
Orange County, CA
Again, thanks for your response. But, I think this is going off course. If the drain plug wasn't in, I would see the water draining; I don't see the water draining. It just seems to endlessly flow into what I presume to be the intake pipe. It hasn't done this in the past. Previously, I would run the hose and fill the reservoir holding the basket to overflowing and then put on the lid. Limited air was then in that chamber and only a minor air bubble was visible through the transparent lid once the pump had primed and slowed. Now, I try to fill the chamber but it won't overflow. Then I quickly try to put on the lid and start the pump, but there is a large amount of air already in the chamber and it remains once the pump has primed and slowed. The pump does prime, there is just too much air remaining. I don't think any new air is being introduced through possible leaks. It's just the air that it began with.
 

mknauss

Mod Squad
TFP Expert
May 3, 2014
18,182
Laughlin, NV
Pool pumps are self priming. You can start them with 0 water in the basket, and if the system is air tight, they will prime and run just fine.

Can you fill out a signature withe your pool type, volume, equipment, etc? Also maybe post a picture of the equipment pad to see if anyone can see something obvious.

Take care.
 

SCRealtor

Member
May 16, 2019
5
Orange County, CA
I don't live at the property (as indicated in my initial post, I am trying to help my folks on their pool) so these are the only shots I have right now. I'll have to take some more next time I'm at their house. There is also a spa. I haven't figured out how many gallons are in their pool.20190515_120852[1].jpg20190515_120852[1].jpg20190515_141711[1].jpg

Just to clarify about priming. I have repeatedly said the pump primes. That is NOT the problem. It is that there is a large air pocket remaining once it has primed. Previously on this pump AND the Pentair pump at my house, I could over-fill the chamber housing the filter basket. For some reason, this pump appears to be draining back into the supply line. I can no longer over-fill this pump. So, it starts with a large amount of air under the lid and maintains a large pocket of air below the lid.

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mknauss

Mod Squad
TFP Expert
May 3, 2014
18,182
Laughlin, NV
If the pump primes and runs without issue, let it be. The air pocket under the pump lid will work out. Do see if the air pocket gets bigger when the pump is off for awhile.

And if the pump is above the water line of the pool, it will always drain back to the pool when you take the lid off the pump basket. Mine does.
 

Texas Splash

Mod Squad
TFP Expert
LifeTime Supporter
I see two issues of concern: cannot fill the pump strainer basket/pot (water runs backwards) and once started the strainer basket/pot doesn't fill to the top. So if the large air gap remains under the clear lid, then something's not right.

To address the lack of (full) water movement into the strainer pot, normally we might gravitate towards a suction side leak, but there's not a whole lot between the pump intake and the ground. I didn't see any comments above about the impeller. You noted cleaning the strainer basket recently, but maybe something got past it and is tangled in the impeller. That would certainly impede water flow into the pot. I would turn off power and check that impeller for sure.

As for water flowing backwards, I'm still thinking that unless there is a significant elevation difference between pad and pool (and I don't think so), there may be an air leak that is allowing water to flow backwards. Remember, air leaks don't mean you'll see a water leak. Often times you don't see both. But I would pay close attention to any hissing or odd sounds when the system is first turned off.

We might also need more info about the spa as your parent's pad equipment is indeed a bit "dated" and has only one gate valve going back to the pool. I think I see a main drain in the pool, but not sure if it's operational. I'm also going to ping our friendly Pentair fan @Jimrahbe who may offer another thought or two.
 

jmastron

LifeTime Supporter
Jul 21, 2014
257
Sacramento, CA
I'm pretty sure that when pump instructions say to fill it with water, they just mean up to the bottom of the inlet, which you should only need to do when first installing or perhaps if the pump ran dry due to a low pool level, not when just opening the lid to clean the basket. They really can't mean anything higher, as noted it'll just drain back to the pool because the lid isn't on and sealed (and once it is, you can't get in there to add more water :) )

My pump takes a short time (~20-30 seconds) to prime, then another few minutes to get most of the air out of the top of the chamber; it often doesn't get it all out, but I don't think that matters.
 

Texas Splash

Mod Squad
TFP Expert
LifeTime Supporter
Something else that may be related to the lack of good water flow through the system is the algae-overload at the moment. I can't make-out the type of filter they have, but if it's jam-packed with algae like I think, water will not flow well and may impacting the pot being full. It does in my pool when the filter is full.
 

Jimrahbe

Mod Squad
TFP Expert
LifeTime Supporter
Jul 7, 2014
12,651
Bedford, TX
SC,

It appears to me that the with a pool that color, no one has asked about your filter... What you are calling "air" may just be the fact that the filter is full and won't let enough water flow out of the pump...

When was the last time the filter was taken apart and cleaned?

Thanks,

Jim R.
 

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