Pumping issues

[rockworthy]

Seem to be having some troubles with my in-ground pool this season.
Here's my setup.
16x32 in-ground
1hp Hayward Super Pump
Hayward DE Filter I think the model is 3600.
Drain on the floor in the deep end.
Skimmer at the shallow end
outlet @ the deep end.
outlet @ the shallow end.
Rebuilt the Vari-Flow valve last year.
I replaced the DE Filter fins about 8 years ago and the have no holes in them.
Pool was installed around 1991 and the pump is original.

Heres the problem.
It seems as though I'm not getting the pressure out of the outlets that I used to get. The outlet on the deep end will flow fairly well but the shallow outlet seems to just trickle after a while. I look in the skimmer and it seems as if the pull into it seems to slow as well. If I shut the pool off for a minute and turn it back on it improves and then the cycle repeats itself awhile later. I run the filter through the skimmer and the drain pulling from both all the time except when vacuuming. I've backwashed about a dozen times and added DE back into the filter but the problem keeps up. The pressure on the filter is reading around 15lbs.

Could my pump motor be going bad since it's so old? It was frozen this tear when I went to start it and I had to take it off the housing and get the impeller to spin then reinstall it, might have been some debris in it. The pump seems to run fine and im not really hearing any funny noises from it. What do you think the cause of the problem is?

 

[JasonLion]

There are several possibilities. There has to be a blockage somewhere. My first guess is that it is time to open up the DE filter and do a really through cleaning and possibly soak the grids overnight (one cup of automatic dish washer detergent for every 5 gallons of water).

How has the filter pressure been behaving? If the pressure is high it is most likely to be the filter, while if the pressure is low it is more likely to be a blockage somewhere on the suction side.

 

[rockworthy]

Thanks for the reply. The pressure is running around 15 psi which isnt high correct? I thought anything over 20-25 psi is in the high range? Where would I look for blockages? Thanks again.

 

[BadOleRoss]

It sounds like your blockage is on the intake side of the pump and filter. You said you had a main floor drain in the deep end and a skimmer. If you can, I would shut off those drains one at a time and see if you can figture out if there is a block in either one. You said that the skimmer seems to be taking water in a little slow, shut off the main floor drain and see if water to the pump realyl flows to almost nothing....that will tell you the skimmer side has the blockage. Do not shut off both intakes at the same time and be careful not to let your pump run dry. You might not be able to shut the drains off like this depending on how your pool is plumbed.

 

[rockworthy]

It sounds like your blockage is on the intake side of the pump and filter. You said you had a main floor drain in the deep end and a skimmer. If you can, I would shut off those drains one at a time and see if you can figture out if there is a block in either one. You said that the skimmer seems to be taking water in a little slow, shut off the main floor drain and see if water to the pump realyl flows to almost nothing....that will tell you the skimmer side has the blockage. Do not shut off both intakes at the same time and be careful not to let your pump run dry. You might not be able to shut the drains off like this depending on how your pool is plumbed.

Thanks, I'm able to shut them off independently of each other. The think that kinda has me clueless is the shallow end outlet is affected more than the deep ends outlet. I'm wondering if there is a blockage maybe in the filter that I may have missed when i hosed it off on Friday. I cant see how the outlet lines would get blocked past the filter could you? It's gotta be on the suction side if it's affecting the flow rate of the skimmer.

 

[BadOleRoss]

Your returns are most likely plumbed like mine, 1 line that goes around the pool with 2 returned plumbed into it. If you put your hand over 1 of the returns does to flow increase at the other return? It really sounds like the suction side.....

 

[rockworthy]

My guess the obstruction would probably be at the filter then. Especially since it goes away and comes back after awhile. I'm gonna blow the inlet lines out tomorrow and see what that yields. After that I'll take the filter apart. It a real pain to take the fin assembly out because it always seems to weld itself in eventhough I lube the tube and o-ring before seating them. Couldn't be the pump is wearing out huh?

 

[BadOleRoss]

I guess the pump could be going bad but I have never heard of a pump fading in/out before going bad. In my experience, they sometimes get noisey and then just lock up or slow down to the pint where they are useless. Blowing out the lines is a good place to start. If you can, remove the return eyes to maximize the openning into the pool. I wonder if there is a pool safe drain cleaner to help break up clogged pipes?

 

[rockworthy]

Problem seemed to go away by itself. Probly a blockage that was dried out from storage then broke apart once hydrated.