Jacuzzi 1UMF-S pump system giving problems

[OshnDoc]

Hello there, I am new to these forums and a one season pool owner, with an about 30000 Gallon pool in northern Mississippi.
I have a Jacuzzi 1UMF-S pump hooked up to the pool with a manufacturing date from 2002.
I purchased the house about 1 year ago.
I had the pump running on a timer all summer long for several hours every day without any problems.
Last fall I replaced part of the plumbing as the Polaris 280 booster pump had problems and the pump head was leaking. Originally both pumps were plumbed in without any screw-type couplings to remove and service the pumps without having to cut the PVC lines. I added several of these joints into the system to be able to service the pumps if needed. -- Well I need them now.

When I opened my pool this year, installed all the drain plugs in the pumps and filter and turned on the electricity, it took a few minutes for the pump to pull the water into the strainer and then into the filter. It ran fine for several days without problems and almost no air in the view glass. I was able to filter, backwash and rinse without any problems.

Now in the last few days it seems as if the pump on start up cannot produce enough suction anymore, and after running for several hours when it turns off, after it established suction and ran, the water almost instantaneously rushes out of the pump and it seems out of the filter as well and the entire topside system seems to be dry, as if there was a large vacuum somewhere in the system.

What am I doing wrong ? What do I need to do ? Thanks a lot for any help.

 

[Bama Rambler]

It sounds like you have a suction side leak. That will cause priming problems as well as back flow issues.

Are you losing water from your pool? You can have a suction side leak and not leak water out when the pump is off.

Can you take a pic of your equipment and post it?

 

[PoolGuyNJ]

Sound like you are a bit low on water or the weir(aka the flapper) in the skimmer is stuck in an elevated position, blocking the water from coming in.

Scott

 

[OshnDoc]

Yes I do seem to be loosing water in the pool when the pool is running. I will take a picture of the pump setup this evening and post it here. Thanks already for the help.

 

[OshnDoc]

Well, I think I might have an actual leak in the suction side of the system. :|

The weir flapper is operating fine. I got the pump primed last night after I replaced an O-ring in one of the drain plugs of the pump, which must have broken when I reinstalled it. The pump ran fine without any bubbles in the view glass and almost no air in the system. The water level was high enough for enough water running into the skimmer and everything seemed fine.

This morning, after letting the pump run all night, the level in the pool had dropped approximately 3/4" within about 7 hours, which indicates a substantial leak to me. This drop in water level caused the pump to suck air through the skimmer at a very moderate amount. The area around the pump is dry, and no visible leaks are in the area.
How do I find this leak I obviously have.

I have currently turned the pump off and marked the waterline to see if this leak is associated with the suction side of the system.

If there is a leak in the suction side, how could I find it? Can there be a problem in the filter valve? I noticed that the area beyond my backwash line seems to be quite wet and I also saw sand in the grass which seemed to have com e from the filter.
The area around the pool where the pipes are buried under is concrete, so I cannot see any water coming from that area.

 

[OshnDoc]

A couple more images

 

[leburch]

Hello,
All of the replies to your problem are incorrect. I had the same issue and two pool companies could not find the problem. The issue lies with the fact that when you repair or replace any underground lines, sand gets sucked through your impeller. The impeller is soft aluminum and the impeller seal is plastic. You are not getting a tight enough seal to produce the same suction you had before the repair. Your local pool shop should be able to pull the motor back from the pump and replace any worn parts. Good luck.

 

[PoolGuyNJ]

Actually, the symptoms are now when the pump is running, he is losing water. The water loss, I will bet, is causing the air's appearance in the pump when it's getting close to the bottom of the weir in the skimmer. The water loss is likely due to a broken return line. A pressure test is called for. If it passes a pressure test, a bucket test with the pump off is called for.

Impellers are plastic on pool pumps with the exception of old Anthony pump and they're brass. Seal sets are typically ceramic and teflon and held together with stainless parts.

Scott