maybe a clog?

[Pr0FiT]

Equipment:
VSP pump
cartridge filter
solar heater on roof


Near the end of last season I noticed that my pool not being heated nearly as much as it was normally would. So looking into it, I found that after the pump was primed the low setting was not pulling through enough water to keep it full, after a few hours it was basically just half-way full. So it seemed like something was affecting the suction and it just wasn't enough to pull the water through. That kind of jived with some other things I was seeing: when open the return line to the pool, it just decompresses; no air comes out and I cannot perceive any water coming out of the return jets...if there's any, it's very slight. I don't remember my exact settings from last year but I'm somewhat sure it was 75% high speed, 15% low speed (clean & heat cycle basically).

Well the season ended and I kind of let it go. So here we are, new year, getting the pool ready to go, sort of the same problem. I currently have the heat cycle set @ 35% speed. The pump stays fully primed, if open up the line going into the solar heater, water comes out, but if I open up the return line, no water. So even at (I think) 20% more power, it's still not enough to force water all the way through, I have to push it up to 45% (maybe 40%) to make it through it seems.

Does it sound like a maybe a partial clog? I don't really see how anything could get past the filter, the line leading out of the filter has such a small screen on it, no way anything of substance would ever get past that. I just cleaned the filter out and do so about once a month so that's not it. Pressure on the filter ready about what it always does. If it is a clog, how would one go about locating and clearing it? Any other possibilities?

 

[pooldv]

What is your current filter pressure on high? And your clean pressure?

My first thought is that you have a suction leak. More here, Pool School - Suction Side Air Leaks

 

[Pr0FiT]

on high (which is 75% max power) I think it's around 15-20psi. Maybe around the same on low speed.

I just went out and found that the valve leading from the solar to the pool was not all the way open. I opened it up all the way, not sure how long it's been like that but I know i haven't touched it since we bought the house a year ago. I also tried to unclog the lines from the pool to the pump by toggling the valves.....a few small branches came out, maybe that was contributing? I'll monitor it tomorrow and update.

Thanks for the link, will read up on it and hopefully that helps.

 

[Pr0FiT]

What is your current filter pressure on high? And your clean pressure?

My first thought is that you have a suction leak. More here, Pool School - Suction Side Air Leaks

So clearing out the lines and fully opening the return value from the solar heater didn't help.

Some more info, which I think supports your idea of the intake side might not be properly sealed. When I first turn on the pump there is a lot of air that comes out of the return jets, at first big bubbles, then smaller fine bubbles after the first minute. After about 15m it seems to clear up or is so slight I can't notice it.

Here is a video of my pump in action at the high speed setting: https://youtu.be/XrXwIZiLCQs . As you can see, there is some air in the basket....doesn't look like a lot to me though but maybe any air is too much air? I didn't take a video but the low setting is about the same, just less turbulent. If the water were at rest I'd say the level is a mm or two above the top of the white basket and the test of the real estate to the top of the lid is air.


I inspected the o-rings on my basket lid and on the junction that goes into the pump...visual inspection looks fine, no cracking, debris, or other noticeable defects. Is this just a case of replace them and see what happens? If so, better or replacing the whole lid or just the o ring?

 

[pooldv]

If the o-ring looks good then usually all that is needed is some silicon lube to help it seal better. That seems like a bit too much air and turbulence.

 

[duraleigh]

That has all the earmarks of a suction side leak. Read the article in Pool School to help you track that leak down. It'll be a quick fix when you find it. As an aside, pay close attention to your pressure gauge......it'll tell you a lot about your pool. (Nice backhand!)