Multiport Valve - Waste vs Rinse?

Exchemist

Well-known member
Oct 5, 2007
86
Philadelphia, PA
I've been looking for a description on how multiport valves work and can only find general overviews. The question of Waste vs Rinse has been bothering me. Can any of the knowledgeable and esteemed members of this board educate me?

When in the "Waste" setting on a multiport valve water flows from the pool, through the pump, and to a Waste port. Simple enough.

"Rinse" is more obscure to me. Let me explain. The filter has two ports, In and Out (when filtering in normal operation). During backwash, water flows from Out to In (backwards) through the filter. "Rinse" is supposed to rinse the filter after backwashing. A proper rinse would require a second In port. Rinsing would have water flow from one In, to the other, and then out to Waste. This is clearly not how Rinse works.

With one In port, all the "Rinse" setting can do is send water by the In port and then to Waste. This seems identical to the "Waste" setting.

What am I missing?
 

no-mas

LifeTime Supporter
Jun 16, 2008
405
FL
Rinse = filter to waste. In other words, in through the in port, through the filter, out the out port, and to the waste line.

Waste = bypass the filter, straight to waste line
 

PoolGuyNJ

TFP Expert
May 20, 2007
3,192
South Central NJ
Rinse is used to remove any debris the got in the "clean" water side of the plumbing when back washing.

Example: Top mount Sand Filter: During filter, water is pushed in from the top. Near the bottom, screen like pipes called laterals collect the water and direct it to the up pipe. Between the two points is a bed of sand. The water passes through the sand which traps any dirt. After some period of time, the top of the sand bed has a load of crud on top.

Backwashing reverses the flow of water in the filter, breaking up the crud. Instead of sending the crudded up water to the pool, it is directed out the backwash/waste port. That also means unfiltered water is now entering the section of plumbing that normally has filtered water. Crud can get in there.

Rinse nearly normalizes the flow. The filtered water goes in it's normal path and flushes any crud that got in during the back wash. After Rinse, the filter is returned to Filter mode.


Waste is used to lower a pool or so what ever is being vacuumed doesn't contaminate the filter tank or plumbing inside the filter.

Scott
 

Exchemist

Well-known member
Oct 5, 2007
86
Philadelphia, PA
Thanks no-mas and PoolGuyNJ. This makes sense.

So, Rinse is similar to Filter, except water is sent to Waste rather than returned to the pool. If you do this briefly after backwashing, any crud loose in the filter goes to waste rather than into the pool.
 

PoolGuyNJ

TFP Expert
May 20, 2007
3,192
South Central NJ
exchemist, close. Any crud in the clean water path gets flushed. Any pool water entering the filter gets filtered. It also resets the sand bed.

During backwash, the sand bed also gets "fluffed up", like a pillow, helping to loosen crud on the sand bed. This is why you you may see some filter sand in the sight bottle during the B/W cycle. The top of a sand bed should be about a foot below the water inlet. The sand is generally too heavy beyond that point to be pushed out from the water flow's momentum.

Rinse also resets the sand bed.

Scott