Pentair variable speed problem

[PoolNewt]

This just came up. I have a Pentair Intelliflo Variable Speed pump. The pump has been working fine until last week when I noticed there wasn't a full bowl of water inside the filter area of the pump. In fact, it's so low, I can see the water flowing into the bowl. I shut it down and waited a bit and restarted. The pump did the usual 30 second prime, the bowl area filled with water and it operated fine. I checked several times within a couple hours and no problem. However, I noticed the bowl wasn't completely full, it was a bit lower where I could see the top of the filter. 4 - 5 hours later, same problem, water in the bowl was very low and I could see the water flowing into it again. I was afraid running like that while not exactly running dry, it's pretty close and I didn't want to damage the pump so I shut it off.

I called Pentair and they suggested a cause could be the water level wasn't high enough. It needs to be halfway up the height of the skimmer. I checked - water level was fine. They asked me my serial number and found it was 5 years old - out of warranty and they gave me the name and phone number of their local rep for my area. I called the local rep and he came out and looked at it. He was a bit puzzled why the water level into the pump was going down, very slowly but definitely decreasing. He noticed air bubbles on the water returning to the pool and surmised that air was getting into what should be a closed system. He checked around but couldn't find any air leak. We also noticed how the pressure on the water coming back into the pool was low. After some discussion he felt the problem could be with the Pentair cartridge filter system - that the cartridges were old, defective, probably getting clogged and putting pressure on the outflow of the water from the pump. He removed the cartridges and with no cartridges, the pool ran fine, no loss of water in the pump filter bowl, His conclusion was to buy a set of new cartridges and problem solved. The cartridges are old, they were the ones when the pump and cartridges were installed - about 5 years ago. While the cartridges had a cleaning about 3-4 months, when they were taken out, they were dirty and needed cleaning.

My questions -
#1 Any one else experience a similar problem where the amount of water in the pump filter bowl was dropping ?
#2 Any ideas of what else could be causing the problem?
#3 is removing the cartridges and running the system without any cartridges a good test of what is the problem and proof that the cartridges needing replacing is the cause of the problem?

Thank you all for your thoughts and consideration.

This along with other pool problems is driving me crazy. I have to be out of town and away for a week and couldn't leave the pool not running the pump for a week. The local rep and the guy from the shop both had to attend Pentair training so they both had to leave town the same time as me and there was some confusion on what state the pump was left in. One guy checked before he left and said he found the pump was off so it could have been left off for the whole week that everyone was gone. But he couldn't tell me the time he was there. The pump is on a scheduled timer and he could have stopped by to check the water level when the pump was scheduled to be off and we are ok. Or the pump was turned off and it's not in running mode so it will be off until someone turns it back on. Regardless, even if the state of the pump is in running mode, the pool would be running with no cartridges for a week until we all get back. I read while it is ok to run the system with no cartridges, the water just won't be cleaned but it is only in the case of an emergency and only for a short period otherwise the pump could be damaged. Asking BING/ChatGPT the answer was: "The system will be under more stress, as the filter will have to work harder to maintain the water flow and pressure. This can damage the pump, the pipes, and the valves, and increase the energy consumption and cost."
I have half a mind to have a friend go over and just shut the pump in off mode until we all get back. Comments?

 

[proavia]

Remove the pump basket lid, clean the mating surfaces, lube the O-ring with silicone pool lube and reinstall.

What RPM was the pump running at when you noticed the air in the pump basket area?
At lower speeds, it's normal to see some air in the pump basket area. Although it sounds like you have a bit too much air in there. Try cleaning and lubing the pump basket area and O-ring as mentioned above. If that doesn't solve the issues, you may have a suction side air leak elsewhere.

Pictures of your equipment pad from a few different angles showing all the equipment and valves might help us see another possible source for the air leak.

Additionally, be more specific with ppol and pool equipment in your signature - manufacturers and model numbers are important. Add what test kit you use as well.

 

[Jimrahbe]

Asking BING/ChatGPT the answer was: "The system will be under more stress, as the filter will have to work harder to maintain the water flow and pressure. This can damage the pump, the pipes, and the valves, and increase the energy consumption and cost."

PN,

What a load of Bull Feathers... !!!

I suspect just temporarily increasing your pump speed would have worked while you were gone.. I am assuming your water is clear and not green..

What size filter do you have??

What speed do you normally run?

Do you have automation?

Thanks,

Jim R.

 

[Newdude]

Also manually flap your weir doors well to verify they aren't sticking. It's a much likelier cause of air in the pump than the plumbing failing in sunny CA out of the blue.

 

[PoolNewt]

thanks for responses - right now I am away from home and will follow up on suggestions when I return home.

Key question - would worn cartridges cause the problem I'm describing where the water level in the bowl containing the filter baseket decreases gradually to where it is nearly empty? This takes about 4 hours.

The pump is set to run 1760 rpm - we tried running it at 2900 rpm and did notice the water level dropping faster - it took about 2 hours to where the level was so low I could see the water streaming into the basket.

 

[Jimrahbe]

PN,

When my filter gets dirty, the bubble under the pump lid gets a little bigger, but the pump never runs out of water.

I can't see how your cartridges could cause this, unless they also caused super high filter pressure..

It sounds to me like you have a suction side air leak, and that your cartridges just make the air leak more obvious.. When the pump is running, the pump generates suction, which is what sucks the water out of the pool. This suction also tries to suck in air at any point it can.. Like from around the O-rings on the pump lid, pump drain plugs, Jandy valves, broken PCV fittings, etc.

Show us some pics of your equipment pad and we might be able to come up with some suggestions.

Thanks,

Jim R.

 

[PoolGoober69]

Run the system without the cartridge in the housing for a few minutes and you'll be able to eliminate the question of the cartridge right away. If everything starts operating as normal, time for a new cartridge.

 

[Newdude]

Key question - would worn cartridges cause the problem I'm describing where the water level in the bowl containing the filter baseket decreases gradually to where it is nearly empty? This takes about 4 hours.

Run the system without the cartridge in the housing for a few minutes and you'll be able to eliminate the question of the cartridge right away. If everything starts operating as normal, time for a new cartridge

Nothing past the pump can create air before the pump. There is a leak or a blockage (clog, stuck weir, etc) before the pump basket.

 

[PoolGoober69]

Nothing past the pump can create air before the pump. There is a leak or a blockage (clog, stuck weir, etc) before the pump basket.

You're assuming there is an air leak. If the pump can't push water past the filter, the pump basket will not completely fill.

 

[Jimrahbe]

If everything starts operating as normal, time for a new cartridge.

69,

I agree, somewhat...

The problem is that even with new cartridges, there is some back pressure.. Obviously, if the old cartridges have a pressure of 10 PSI and the new ones have a pressure 2 PSI, the cartridges need to be replaced.

Taking the cartridges out completely makes the water flow easier and I think might hide the fact that there is a suction side air leak.

I have no proof that this is true, it is just based upon my experience with my system..

Thanks,

Jim R.

 

[Newdude]

. If the pump can't push water past the filter, the pump basket will not completely fill.

IMO it will push the air out first, then simply push less water due to the restriction.

However. The pump basket starts full and then fills with air slowly. No restriction downstream will make a full pump basket suck air. So there is an air leak or restriction upstream.

 

[PoolNewt]

We did take out the cartridges and ran the pump. No problem. No water decreasing in the bowl even running for hours. So the pool guy says problem solved, just buy all new cartridges. I like this discussion as I'm still concerned about the air bubbles and wonder if there is a suction side air leak. How do I go about trying to find where the air leak is without tearing things apart. For example,I do have a heater this is no longer used. I would have to cut the pipes to get around the heater but even though the heater hasn't been used, it would be nice if there was a way to isolate something like the heater without cutting pipes. Wait - the heater isn't on the suction side. But you know what I mean - how to test where the air is being sucked in.

I will take some pictures and a video of the bubbles. Also pictures of the piping but it is kind of convoluted. I will send that out on Monday after I get back home. Headed for home tonight. Thanks all !

 

[Jimrahbe]

PN,

I like the idea of showing us several pics of your whole equipment pad, especially the suction side.

Thanks,

Jim R.

 

[Newdude]

how to test where the air is being sucked in.

You need to witness the bubbles forming to rule out everything at the pad before the pump. If it's leaking you can soak the unions/valves/fittings with a hose and the bubbles will stop if you hit the right spot.

 

[bregobob]

My new pump fresh from the factory packaging unknowingly was installed with over a 0.035 gap between the pump housing and the motor adaptor plate with surface to surface contact at the bolt sites. It seems to me this condition could have been caught by PENTAIR QC but was not. This condition could be the site of my air leak since the seal is only a few mills thick with housing bolts 3/4 turn loose. You might need to consider this possibility when looking for an air leak. I, like you am a homeowner looking for a solution.