Hi Pan,
It really sounds like you have it backwards.
Slide valve should be up in normal operation.
Valve should be down during backwash.
Yes the valve locks in either up or down position.
No it should not get sucked down unless it is plumbed wrong.

Here is a picture, hope it helps.
{{!gwi}}

The valve operates 2 ways, one for sand and one for DE.
The following is directly from the slide valve manual - SLIDE Valve For Pentair Sand and DE Filters #261165 2"

SAND Info
Sand Connection: Valve top connection - to waste, middle connection - from pump, bottom connection - return to pool

Sand operation: requires Handle up for filtering and handle down for back washing.

DE INFO
DE Connection: Valve top connection - return to pool, middle connection - from pump, bottom connection - to waste

DE Operation: requires handle down for filtering and handle up for back washing.

I hope this helps....

Casey,
You are wrong on this filter.
This is not a normal DE filter, it is a QUAD DE. When you use a slide valve with a QUAD you plumb it like a SAND filter, not a DE. You must read the directions of the filter. When you plumb it as you have it, it will EXPLODE the $400 plus cartridges.
We have installed many of these, plus I have one in my own backyard.

Casey,
PS, I just noticed it was your post that I gave this info out earlier, are you trying to spread your misery?
Here is a link to the owners manual, though it is not very clear, and why many "not so bright" individuals plumb it incorrectly.
Check out the "Caution" on page #3

Here is a link that might be useful: Quad DE owners manual

This is the 1st Quad DE I have installed. I was only stating what is in the filter valve manual. The filter user manual warning says that it is different than other DE filters and you must use one of the valves listed. I followed the slide valve installation for a DE filter assuming that Pentair accounted for the filter difference stated based on their recommendation of valves.

It sounds like you have a lot of experience with this filter. Looking at your filter picture, I have the pool return and waste lines swapped. My filter is operating with the slide valve in the down position.

The thing I don't understand is the filter would then be running in backwash mode the way I am set up. I would expect all of the DE dumped in my pool but that is not happening. The water is actually really clear with a small amount of DE leakage in the pool during startup.

I have sight glasses on each of the lines and can see the DE rushing through the waste line when the valve handle is in the up position. Did the DE coat the inside of the filter cartridges instead of the outside of the cartridges?

Can you help clarify this before I replumb the connections? Do I need to open the filter and wash everything down before restarting after I replumb?

Casey,
Your cartridges are working backwards, all of the DE and dirt are on the inside of the cartridges, not the outside where it belongs. Again they are not meant to run this way, so when you crack open the filter, you will see they are all blown up like ballons and starting to split. Per your other post, this is why you have DE in the pool, and why your pressure has not changed at all. Sorry to be the one with the bad news. Many, many skilled installers have made the same mistake.

"The thing I don't understand is the filter would then be running in backwash mode the way I am set up. I would expect all of the DE dumped in my pool but that is not happening. The water is actually really clear with a small amount of DE leakage in the pool during startup. "

You are coating the inside of the cartridges. The cartridges will stop the DE no matter which way the water flows. It will just be a smaller surface area, with the flow pushing the element away from it's core instead of against the core.

Pb,

You were dead on with this one. That exlains the DE in the pool. Three cartridges are swollen and the fourth is torn at the top gasket. Very frustrating. I reread the instructions and wish the instructions were clearer. The only indication is the warning which says to use the recommended valves. Ouch, thats an expensive mistake!!! Pentair should take some ownership for not clealry documenting the install instructions

Do you know the life span of the cartidges under normal use? Does it make sense to sell the Quad DE filter (out of frustration) at this point and go to a sand filter to eliminate future problems and minimize maintenance? A sand filter will cost the same as repaiirng and replumbing the Quad DE 60.

You would be going from a corvette to a yugo. The DE works so much better. I have had a Quad on my pool for 3 years, the grids are very strong, so I dont know exactly how long they will last. Plus I am pushing a 3hp pump through it, which really tests it.

See if you can clean the dirt and DE out of the (not torn) grids, and just replace the one, and replumb it.
Trust me Pentair has gotten a lot of flack for this. Ultimatly on the front of the filter it has a label "INLET"
and "OUTLET", so you would be fighting a losing battle.
I take it you installed this so there is no one to go after.
Good luck.

just-a-pb

my pool was completed a few weeks ago. I too have this filter. The plumber put in a "sand filter valve." The water is crystal clear. If it were plumbed incorrectly or the wrong valve used, would the water still appear clean?

Thank you.

Mike. I have the Quad 80 with the sand filter valve. But that's only after I blew up all 4 cartridges by using the DE valve last spring.

You got it right.

Mike,
To answer your questions yes it would appear clean, and work to filter your water for a while. Basically if it was done backwards then you would be coating the inside of the grids with DE, and water would be passing through that filtering the water.
This works till the grids blow up from the pressure, then DE is released into the pool, and you get an expensive bill.

It plumbs using the sand configuration so that should be right.

If you are unsure, you could open the two unions going into the filter, and bump the motor to see verify inlet is inlet, and outlet is outlet.

I beleive Pentair DOES take ownership on the install by the YELLOW tag on the valve that clearly says how to install.