vacuum problems

[appwps]

I have been cleaning this pool for a year now. I never had an issue with the vacuum untill a few months ago. I use the filter setting to vacuum the pool and I always keep the skimmer basket in while I vacuum (so I don't think that the pluming is clogged). It starts out with good suction for about five minutes then gets real weak. The only way I get it to work better is to put in on recirculate for a few seconds then put it back on filter. It works for a few minutes but then gets weak again. I have to repeat the actions above untill the pool is vacuumed and it is getting really old.

Again, I don't think the pluming is clogged. The skimmer basket is not full (I am just trying to vacuum dirt, no leaves). The pump basket is clean. The filter works fine in every day filtering, it also wastes and backwashes fine.

Any thoughts?

Thanks,
Chad

 

[Bama Rambler]

What type of filter and how long since you've cleaned it really well?
What's the filter pressure normally and when vacuuming?

 

[appwps]

Thanks for the reply

This is a customers pool which is a rental house, so I do not know any specifics on the sand itself.

I have been cleaning it for a year and I have never cleaned the sand.
As far as the guage....I do not think that it works properly, it always reads high and it looks realy old. This is one of those customers that doesn't spend any money on up-keep for the pool. I know that the guage reads high and when I vacuum the needle jumps almost half way around the guage.

Thanks
Chad

 

[JohnT]

What does the gauge read when you shut the pump off?

 

[appwps]

Here are the gauge readings

When the pump is off----24
waste------------------29
backwash-------------- 35
filter--------------------the gauge is maxed out
Vacuum----------------needle bounces from 25 to 35 and everywhere in-between

the gauge only goes to 30 but at backwash and vacuum settings the needle is about where a 35 would probably be.

When I backwash the filter the sight glass clears up fairly quickly, so I don't think it is dirty.

Thanks
Chad

 

[Bama Rambler]

Sounds like that filter needs a really good backwashing and maybe even resettling.

You really can't tell what's going on with a bad gauge. If it reads 24 with the pump off you can't trust the rest of the readings at all. They need a new gauge!

 

[JohnT]

The bouncing needle sounds like the pump is sucking air. Maybe the vacuum hose can't supply enough water to it. Does the pump strainer stay full while vacuuming?

 

[appwps]

I do believe I will try to talk them into getting that new gauge.

No, the pump strainer does not stay full. About a third of the strainer fills with air. So should I leave the main drain open when I vacuum to help it get enough water?

Great trouble shooting guys, thank you for all of your help.
Chad

 

[JohnT]

I do believe I will try to talk them into getting that new gauge.

No, the pump strainer does not stay full. About a third of the strainer fills with air. So should I leave the main drain open when I vacuum to help it get enough water?

Great trouble shooting guys, thank you for all of your help.
Chad

Leave the drain partially open.