pulsating pump/filter basket

[ncbrit]

When I turn on my pump, regardless of where I have the filter switched to, i get a pulsating action. The water level in the baseket increases, then the pump forces the water out to the returns, and then the water level in the basket drops. As the basket fills back up, the action repeats. It does this set to filter, backwash, & circulate.

It only does it when the pump is on high speed. The pressure gauge swings back and forth in time with the pulsating action. When the pump is on slow speed, i get a slow but regular flow through the pump/filter.

What could cause this. It seems to me that the line from the skimmer could be partially blocked, to where there isnt enough flow from the skimmer to keep up with the pump. If thats the case, how do I cure it? I could cut one of the lines, and stick the pressure washer down it. However there is not much space betwen the ground and the pump to re-join the skimmer line. Would it be ok to cut the line between pump and filter, and run the pressure through the pump, and therefore down the skimmer line?

 

[Richard320]

Look for low water level in the skimmer, or a stuck weir (the skimmer flapper). Also check that you don't have a lot of air trapped in the filter.

 

[ncbrit]

Water level is high from all the rain over winter. I was trying to run some to waste. How do I check for trapped air in the filter?

 

[Richard320]

Water level is high from all the rain over winter. I was trying to run some to waste. How do I check for trapped air in the filter?

Open the air bleed until water comes out. Although I looked up the filter in your signature and it looks like you may not have an air bleed since the outlet is already at the top.

 

[ncbrit]

yeah, theres no air bleed valve. I tried running a regular hosepipe down it for a while, but nothing changed. I think i'm going to have to cut one of the pipes, or try to find some kind of 90 degree attachment for the pressure washer to try and blow out the skimmer line. All my plumbing is glued hard, so I cant just unscrew the joints.

 

[ncbrit]

after reading this, pump-strainer-basket-issue-t41008.html

i think i found the issue. I could hear air hissing in the area around the motor/pump housing. I unbolted the motor, and found a small area where the o-ring was pinched.

 

[ncbrit]

That didnt fix it. I replaced all the seals in the pump, and also the one at the strainer lid. It still fills then empties, fills then empties. I also noticed that the returns blow then suck, blow then suck. I put my hand over the skimmer suction hole, and noticed that the suction pressure seems really weak.

I think my next step is to try a drain king to blow the skimmer line backwards.

 

[Bama Rambler]

That's probably your easiest to try. If that doesn't work it's off leak hunting.

 

[ncbrit]

I purchased a cobra at lowes. I did get flow through the line, but I cant tell if its losing any along the way, due to the high water level in the skimmer. I would need a way to measure the pressure in the line. I have a long thin steel fish tape (electricians kind) that I'm going to try. If its a leak, I'm 100% confident its not at the pump, and must be underground. With the skimmer line being suction, wouldnt I see dirt in the water that enters the strainer though?

 

[duraleigh]

I would assume your underground pipes are fine....they almost always are. You are sucking air into your system somewhere between the skimmers and the pump.

Even if the pipes are clogged (and it sounds like they are not) you are still sucking air into the system. finding that air leak will solve the problem.

Did the hissing near the pump stop?

I assume you have checked the most common place for that to occur....the o-ring around the pump basket lid.

 

[ncbrit]

Yes, the hissing stopped. I replaced all three seals including the o-ring around the pump basket, and used magic lube on them. Its what they had at the pool store. I've also tried running a water hose over the usual suspect areas, and it doesnt help.

I'm thinking its probably time to call in the professionals.

 

[Melt In The Sun]

Have you checked the drain plugs on the pump? That's another common place.

 

[ncbrit]

I put PTFE tape around them when I first had the issue, I could take them back out and reseat them with some of the magic lube on them.

 

[ncbrit]

Pool guy has been working on it on and off for the last week. First he took the pump apart. No issues there, so at least I know I replaced the seals correctly. Then he pressure tested the skimmer line. No issues there either. Determined that it must have been a clog. He tried blowing it out, and couldnt get it moved, and was planning on bringing a higher pressure pump. Then yesterday he called, and said he had gotten a wad of leaves and pine needles out using a sewer cleaner with a corkscrew device on the end. Everything is flowing good now, and I have the shocking process underway

 

[Bama Rambler]

Whoohoo!

Glad you found it and got it out of there, even if you did have to employ help.