Do all filters have a multiport valve?

[Unknownhavoc]

I have been reading about vacuuming and saw someone mention 'vacuuming to waste' I research that a bit and see that some filters have a multiport valve that allows them to perform different functions. Do all filters have these? I found the manual for my pump and nowhere does it mention a multiport valve, back washing, waste, etc.

Am I missing something, or do I just vacuum directly into my skimmer?

Thanks

 

[Texas Splash]

No they don't. Normally you'll find them on sand and some DE filters. They look like this:


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If you're like me with a cartridge filter, you will connect your hose to the skimmer and vacuum directly into main filter.

 

[Unknownhavoc]

So if my pump doesn't have a MPV, I guess I couldn't vacuum to waste? I did some more research and it looks like it's a 'sliding valve' that automatically switches the filter to backwash when the bump handle is pulled up.


Got it! Thanks!

 

[Richard320]

So if my pump doesn't have a MPV, I guess I couldn't vacuum to waste? I did some more research and it looks like it's a 'sliding valve' that automatically switches the filter to backwash when the bump handle is pulled up.


Got it! Thanks!

That's a push-pull valve and it's only used for backwashing. There is no recirculate or waste position on that type. All it does is reverse the flow through the grids and direct the dirty water out the waste pipe instead of back into the pool.

Attempting to vacuum with the valve in the backwash position can wreck the screens. Normally, water flows from outside to inside and then back to the pool. The DE powder cakes up on the screens. Anything you filter out whether from the skimmer or vacuuming ends up stuck to the outside of the DE. When you backwash, it gets pushed off and out. If you try vacuuming on backwash, the stuff you're vacuuming will end up inside the grids (where there is no DE to cushion them, so things can damage the fabric) and not out the waste pipe. And then as soon as you return to filter, most of that stuff will get blown back into the pool. And what doesn't will likely be forever stuck inside the grids.

 

[Kiss4aFrog]