Pump not priming pool side

[Poolser]

My pumped stopped priming on the pool side. When I turned to spa side, it would prime properly which makes me assume it it something between that valve and the skimmers. I tried using a bladder in both the pump side as well as skimmers. When doing this, I would open only one skimmer valve at a time.

Some notes: not sure how related any of this might be.
The skimmer nearest the equipment has been murky for some time. At first it seemed as the water was clear until I would reach in for the basket and then it would just get all cloudy when there was any sort of movement. Now, it just seems murky all the time. This never seemed to affect the other skimmer until today when doing the bladder flush I noticed the far side got murky too.
Before the pump stopped priming at all, it was intermittent. At first it seemed when the pump first started it wouldn't prime. I thought there was some communication issue between the wireless unit and the unit by the equipment. I say this because I would shut off the pump and then restart it and it seemed to prime properly. I noticed this for a few days. Again, right now it won't prime at all.

I'm new to pool ownership and have been trying to read these forums and youtube videos for tips. I've ruled out o-ring and multiport since it seems to prime fine with the spa.
Location: North Texas (never lost power during the winter storm and everything "seemed" to work fine after it)

In the picture, the furthest left is labeled spa, on the right side they are Skimmer, Skimmer, Main Drain. I'm personally not sure where the main drain is on the pool as I've never seen any sort of drain in it.

 

[ajw22]

Welcome to TFP.

You have three lines with valves going into the pool side suction. What do those three lines go to? Two skimmers and a main drain?

Have you tried to run the pool pump with two lines off and one line on? Try each line alone? Or combinations of two lines on and one line off?

 

[Poolser]

ajw22 -
Correct, 2 skimmers and main drain.
I have tried each of them alone and still no suction. I don't see any water flowing through with any of them. I tried the spa side again and was able to get suction and a prime going. There did seem to be some air bubbles in the system when just on spa side but maybe that is due to sizing? I've tried running a hose over everything and that didn't seem to stop it either.

 

[ajw22]

I would pull the actuator off the suction side diverter and open up the valve and examine the diverter and make sure nothing is broken inside the valve such that it is not properly working.

I might also try moving the valve to the proper position manually with the actuator off.

Three suction lines all going bad is unlikely. To me the problem is in the valve.

 

[Poolser]

I took the actuator off, looked at the diverter and no issues. I also took off all 3 of the skimmer/main line valves and re-did the bladder test. I was getting water flow in both directions to/from pump. All of the valves looked fine too. I put lube on everything and put them back on and still no suction. I also put saran wrap over all the pool side pipes (have run water over them before too) and that didn't seem to help.

I do agree it is odd that it could be all 3 suction lines. I just don't know what else to try at this point.

 

[Poolser]

Update - I messed with all the valves again, turning all off but one, etc. I was able to get it to prime off one skimmer and the main drain. The second skimmer was getting some water flow finally but it wasn't enough to get to priming the pump. So I think I have isolated my issue to that skimmer. Now the question is what that issue might be. I assume I'm ok to run the pump with just the one skimmer and main drain?

 

[ajw22]

Yup, run the pool with one skimmer and the main drain.

Glad you figured out which line was causing the problems.

 

[Poolser]

Yes. Thank you so much for your help. Not sure what actually worked or if I was just an idiot the entire time and just that one wasn’t working. I had given up before you kept having me try new things. Thank you!!

 

[Poolser]

So after about 3 hours I lost suction again. I’m now wondering if it might be a problem with the pump. It is a variable speed pump and know it goes to lower speed over time. I wonder if it’s not enough to hold the suction any longer. That might also make sense of why the one skimmer will flow but not prime - it is the furthest from the pump. Does this sound logical? I’m not sure the age of the pump but it did run like a champ during the Texas freeze for nearly 2 weeks straight. Maybe that was too much for it?

 

[Poolser]

found this previous post which seems similar to mine. Now wondering if it has to do with the filter.

Pentair pump - will only prime when I trick it - any time Variable speed drops below near max, it won't prime again

Pentair Intelliflow 2 VST Pump - about 3 yrs old. Pool recently opened, pump was primed and running. I noticed one day later my pump was not running and reason was it had not primed (if it can't prime after 11 minutes, it goes into an error state.) So I did the following: (1)...

www.troublefreepool.com

 

[ajw22]

What speeds and times is the pump set to run?

 

[Poolser]

What speeds and times is the pump set to run?

It looked like it was running at 2850 for 10 hours. I increased to 3000 but I’m still losing prime after about 1.5-2 hours.

I’m about to backwash and inspect my DE filter but I wanted to try and let the pool run as much as I could while watching it so it will start to clean out a little. My filter pressure is normally around 20 psi after backwash. Right now it has been shooting up to 36 when the pump first starts but then settles down to 26 after the first few minutes.

 

[ajw22]

No pool should need that much RPM and flow.

Disassembling the filter should be your next step.

 

[Poolser]

Thanks. Did that. I would post a picture of it but don’t want to win worst looking DE filter ever. I had backwashed once in past 4 months since I’ve been here but that must not have done too much.
I haven’t been able to clean it yet due to no water from another project I started today. So hopefully tomorrow I can get it cleaned and see what happens.

 

[Poolser]

Hopefully this is my final update. Completely took apart the disgusting filter and cleaned it. I didn't get to a TSP/Acid wash but gave it a really thorough cleaning. I do have a few minor cracks in the top parts of a couple grids and a couple have the top holder piece broken (but they seem to work for now). Put it all back and recharged it with some DE. Pump seems to be doing fine and haven't had any issues after 3 hours of running (including turning down the RPMs). I was even able to open up the 3rd skimmer line with no issues.

Moral of the story: clean your filters! I didn't think that would have caused the suction issues but think it was going on for some time since well before I had moved in. I had backwashed once but think it might have been too nasty for that to even help too much. I'm going to go ahead and attach some pictures of the filter. This was even after I took off a layer of DE/sand/dirty from the top.

ajw22 - Thank you again for all your help!