Loss of pump head

JimmyGee

Member
Jun 16, 2022
11
Long Island, NY
Apologies in advance for the long description…

20+ yr old 20x40 36,000g in-ground pool with a DE filter setup (ProGrid 4820). I’ve been removing and reinstalling the filter/motor etc for 20 years without an issue.

This year upon assembly the pump motor didn’t run. I replaced the capacitor to no avail, then replaced the motor with a Century exact replacement. I do t have the specs in front of me but I’ve done this before and was pretty careful to match RPM and look at the pump curves. I’m a Chem Eng by formal education.

I then proceeded to create a HUGE problem by purchasing and charging the filter with what I thought was DE, but was Perlite. At one point the filter was over saturated with the stuff and it was passing into the pool. I also - for the first time - could not maintain suction with the vacuum connected to the skimmer.

I finally got rid of the Perlite by repeatedly brushing the pool and running the filter 24x7. It took more than a week, but finally cleared up. The loss of suction with the vacuum problem still remains.

After 3-4 weeks of use, I was getting some algae growth around the perimeter. Had the water tested - Chlorine and phosphates were way too high (15ppm and 1200, resp.). I was advised to turn the chlorinator off for a few days and use PhosFree. As I should have guessed the pool immediately turned into a green swamp. After running by filter for another 5-6 days (and backwashing the filter 2-3 times) it is still green and swampy (chlorinator went back on when Cl2 was in range) and I can see a ton of what looks like DE on the bottom of the pool. I desperately want to vac it to waste, but cannot maintain suction.

My questions are not about pool chemistry - if needed those will come later - but about the suction issue.

While running the suction from both the main drain and the two skimmers, the system runs fine. There is air coming from the discharge jet, and if I leave the bleed on top of the filter cracked it will constantly sputter.

If I divert the suction to EITHER the main drain OR the skimmers, I can see the water level dropping in the filter basket and it will eventually lose suction.

At first I thought maybe I had a leak in the line, but since the skimmers and main drain have separate lines, that’s not logical. The lines come up from the ground and are connected at a single directional valve that is inches from the pump. I’ve removed the pump connection/union, replaced the o-ring, checked it for level and tightened the coupling. I’ve also rebuilt the pump head.

It is possible that the air and vacuum loss are unrelated. I am wondering if air is causing the issue - or could the lines leading to the pump be clogged with perlite? The stuff is a bit sticky and almost like glue - I had to get a rag with some soap to clean it off the inside of my filter.

I don’t have a setup to leak test. I went and saw someone weeks ago to come leak test, but despite me giving them my CC they never showed.

I also ordered a boroscope today to snake down the skimmer to have a look.

Any/all ideas/advice welcome.

Lastly - is it possible to connect the vacuum directly to the pump head union? I don’t see how I could get a tight connection or fill the 50’ hose sufficiently with water to start the suction - but someone suggested that to me. Again - suggestions appreciated.

Thanks in advance -
 

ajw22

Gold Supporter
TFP Guide
Jul 21, 2013
37,869
Northern NJ
Pool Size
35000
Surface
Plaster
Chlorine
Salt Water Generator
SWG Type
Pentair Intellichlor IC-60
What model pump do you have?

How many skimmers do you have?

Post pics of your equipment pad so we can see your situation.

Please create your signature with details of your pool and equipment. It lets everyone understand your setup without a lot fo back and forth questions.
 

JimmyGee

Member
Jun 16, 2022
11
Long Island, NY
The pool is a vinyl liner 20x40 with 2 skimmers. The skid is a Hayward setup. The pump is an SP2600, and the motor I installed this season is a 1-1/2hp Century UST1152, 3450 rpm. The suction side is very straight forward - the skimmers and main drain are piped to a “dial-a-flow” valve to select either or both. The valve feeds a short section of 1-1/2” pipe to a union that allows removal of the pump. After the pump there’s a multiport - the DE filter and back to the multiport. The discharge side has a small 3/4” takeoff for a fountain, another for the Polaris 380, the chlorinator, and then another dial-a-flow valve to either the main jets or the jets in the steps. It’s late and I’ll see if I can post photos tomorrow.

Re the pump - I replaced the pump head and shaft seal etc.
 

ajw22

Gold Supporter
TFP Guide
Jul 21, 2013
37,869
Northern NJ
Pool Size
35000
Surface
Plaster
Chlorine
Salt Water Generator
SWG Type
Pentair Intellichlor IC-60
I can't see any details between the small size of the pic and the plants around the equipment.
 

JimmyGee

Member
Jun 16, 2022
11
Long Island, NY
Apparently the boroscope was a wasted $80. Between the poor resolution and poor lighting - and limited ability to push the camera cable through - I couldn’t see anything.

I disconnected and pulled the pump aside and used my shop vac to blow the line to the skimmer. The water was a bit cloudy and there were some small white granules that washed out. Reassembled the pump motor and no change in performance. If the suction is from both the skimmers and main drain - there is a lot of sputtering of air coming out of the bleed valve of the filter - but the system runs. If I switch the suction to the skimmers - the level in the pump basket immediately drops to about 25%, the flow is greatly reduced, and from prior experience the pump will ultimately begin to cavitate. If I switch the suction to the main drain only the same issue occurs, though at a much slower rate.

I am at a loss as to where to go next. Advice/suggestions appreciated.