Pump strainer basket "cycling"??

[Vettepilot]

Will do, thanks. Never saw that weird "cycling" thing before. But you other repair men know the situation... sometimes you know deep down what needs to be done; you just don't want to go there!!

Vettepilot

[Vettepilot]

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[Vettepilot]

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[Vettepilot]

I don't know what's going on. It wouldn't post my reply, then I think it posted several times.

Moderator, help!?

Vettepilot

[Denniswiseman]

If you tried to post ...... then it wouldn't because it's to short and isn't really anything
BTW I'm not a moderator and I doubt if anyone is moderating

[Vettepilot]

Well no. It was my post that starts with "Will do."

It posted it 3 times. So I went back and tried to delete them. Minimum number of characters is 6, so I put 6 periods.

Oh well...

Vettepilot

[Denniswiseman]

I tried something similar and it rejected my post as well

[Vettepilot]

Ok, a last update on this puzzling case, in order to help others. It's an odd one...

Again, I had very low filter pressure, and the pump strainer basket would slowly fill up with water, then "whoosh!", the pump would empty it and start the process over. This happened on an approximate 20 to 30 second cycle.

Many kept saying "vacuum leak". I did not feel this was the issue, partly because of how this system is configured and partly because I could feel vacuum on the basket lid when I would unscrew it. But, I spent a good bit of time searching for leaks. Finally, I rigged up and performed a pressure test on the vacuum side. No leaks.

I then disconnected the pressure side from the filter, (a real pain in this case), and fired the system up. Almost zero flow. So, I pulled the pump off, and performed a complete rebuild. The pump WAS worn, and a rebuild was in order anyway.

All back together, and NO CHANGE!!

Long story short, I found a BLOCKAGE in the suction line!! There are two 90 degree elbows near where the suction line enters the pump. When I cut it apart, I found 3 little vacuum head brushes, and a small piece of rope with a tiny swatch of inflatable pool toy lodged in one of the elbows.

NOW, all the syptoms made sense!! The "cycling" was the pump struggling to suck water past the obstruction, and slowly filling the basket. When it would get the basket full, the pump would prime, and suddenly suck all that water out of the basket, only to do it again, over and over!! With the obstruction removed, the system works perfectly; actually better than ever due to the now fresh pump.

Moral to the story? Vacuum leaks are a fairly common problem, but they are not the ONLY problem one can encounter. When something is really puzzling, think outside the box for an answer. My favorite thought: "If a man made it and it worked before, a man can fix it!"

Thanks,
Vettepilot

[Teapot1]

Thank you for returning and telling us what you found, most certainly a blockage would cause it as it limits the flow. Please also remember that from behind a PC its no where as easy to diagnose faults compared to being at the scene of the crime. Air leaks are far more common than blockages as the skimmer basket would prevent most things from ever getting into the pipework.

[Denniswiseman]

The blockage put an extra load on the suction and did cause a suction side air leak albiet under normal conditions wouldn't happen
How was it possible to get those parts into the pipework

[Vettepilot]

Well, think about it. When hooking up many vacuums, you remove the skimmer basket, and plug the vacuum hose into the suction port below. So the flow is virtually un-filtered from the vacuum head itself, all the way to the strainer basket near the pump, where it is filtered, or strained actually, by the pump strainer basket. But all the vacuum hose and plumbing itself is not strained. In this case, his vacuum head had multiple 3" long brushes on it, and 3 of them broke off and got sucked into the system. They made it nearly to the strainer basket, but were stopped near the basket in one of the two 90 degree plumbing elbows. I believe the system worked at that point, but with severely reduced flow. The killer was at some point while vacuuming, a small swatch of old pool toy, attached to a 3" long rope remnant got vacuumed up. That would probably have made it safely into the strainer basket and not caused a problem, but it was stopped by those 3 brushes stuck in the elbow. This formed a nearly closed off blockage.

Anyway, this system is different. At some point in the past, about 2 years ago, he suspected an underground leak in the suction piping. So he ran a direct line from the shallow end of the pool, up to the existing inlet plumbing going into the pump. This new inlet line has a one way check valve with a strainer on it at the inlet, and has a "Y" with on/off valves. When he wants to vacuum, he hooks up the vacuum hose to the "Y", and cycles the valves. Again, the flow is not strained while vacuuming just like the original system, until it gets to the strainer basket.

This all worked fine until something too long and stiff to pass through those two 90 degree elbows before the strainer basket got vacuumed up, and blocked flow.

I'm just glad it's fixed, and I advised him to securely GLUE the brushes into place on his new vacuum head! (I have found "Shoe Goo" from Walmart to be a very strong, durable, and tenacious glue for a job such as this.)

Thanks,
Vettepilot

[Denniswiseman]

Right, I don't remove my skimmer basket when vacuuming, there is a circular plate on top with a hole which takes the vacuum
It may be a good idea to form some type of trap before going into the return line

[Teapot1]

Quite right Dennis, very poor idea vacuuming without the basket in place as things will cause blockages be it leaves or otherwise. If the skimmer doesnt come with vacuum plate (kornea plate) then I suggest finding one.
I often supplied one to customers if they didn't have one. One of my favourites and the one I use myself is a Certikin as its easy to belt sand the outside to fit a wide range of skimmers.
Certikin POOL SKIMMER VACUUM ADAPTOR KORNEA https://www.amazon.co.uk/dp/B079M3J73X/ ... XJVACWS64K

[Vettepilot]

Very, very good idea. I've given some thought to creating a trap and/or strainer for while vacuuming with this guy's unique-modified system. Could prevent a lot of grief.

Of course, over the past decades I've vacuumed hundreds and hundreds of times on systems with no vacuum strainer with virtually no problems, but still...

Vettepilot

[Denniswiseman]

You only need the once to really muck things up