How a Multiport Valve Operates

WRITTEN BY:  Inyo Pools

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There are three major types of pool filtering system: cartridge, sand, and diatomaceous earth (DE). Sand and DE filters use a multiport valve primarily to help clean or backflush the filter media. Cartridge filters do not have multiport valves. These filters are cleaned by removing the cartridge and spraying it with a garden hose. A typical multiport valve has 7 settings: filter, backwash, rinse, waste, closed, recirculate, and winter. This guide explains the function of these setting and shows how they circulate water in a typical sand filter. The operation of a DE multiport valve is very similar.


Step by Step


Step 1

There are five ports into and out of a typical multiport valve. Three are shown in this picture. The top left port, labeled "PUMP", brings unfiltered water in from the pump. The middle left port, labeled "RETURN", sends filtered water back to the pool. The middle right port, labeled "WASTE", sends water to an external drain hose.

Step 2

The other two ports control flow though the filter. This picture shows the valve as it is connected to the inside piping of the filter. At the bottom of the valve, a pipe port connects to the collection tubes (laterals) on the bottom of the filter. The area around the pipe on the bottom side of the valve directs water to the top of the filter. This picture shows water flow for a "FILTER" setting. Water will flow in the opposite direction with a "BACKWASH" setting. The next series of steps explains how each of the valve setting directs water though these ports. CAUTION. When selecting a valve setting, make sure that the pump has been TURNED OFF and always depress the handle before turning.

Step 3

FILTER. This is the normal setting for filtering your pool water and for regular vacuuming. Water from the pool is pumped into the "PUMP" port to the top of the filter. Contaminates are removed as the water makes it way to the bottom to be pushed back up through a central pipe to the "RETURN" port and back to the pool.

Step 4

BACKWASH. After a period of time, the contaminates start to clog the sand to the point where water flow is significantly diminished and the pressure gauge rises 8 to 10 psi above normal operation readings. To clean out the contaminates, you have to backwash the sand. In the backwash setting water flow is reversed though the filter. Water comes from the "PUMP" port down the filter through the central pipe, then back up through the sand to flow out the top exit of the filter and out the "WASTE" port to an external drain. As the water flows up though the sand, the sand is lifted about 7 inches above its normal height releasing the trapped contaminates to be purged out in the waste water.

Step 5

RINSE. After backwashing, the sand is loose and needs to be reset. Also any dirty water from backwashing has to be rinsed out of the filter to waste to prevent it from returning to the pool. With the valve in rinse mode, water is directed from the "PUMP" port to the top of the tank to compress the sand. As in the filter setting, the water flows down though the sand and back up though the central pipe but instead of going out the "RETURN" port to the pool, the water is diverted out the "WASTE" port.

Step 6

WASTE. This setting is used to bypass the filter when you want to vacuum the pool after an algae treatment or to lower the pool level. The water enters the valve though the "PUMP" port and exits though the "WASTE" port.

Step 7

CLOSED. This setting is used for shutting off all flow to the filter and pool. Water flow is stopped at the "PUMP" port.

Step 8

RECIRCULATE. This setting is used to bypass the filter during certain pool cleanups and chemical treatments when you don't want the water contaminating the sand. Water enters the valve through the "PUMP" port and exits back to the pool through the "RETURN" port.

Step 9

WINTER. Use this setting when you are closing down the pool for the winter. This will allow water to drain from the valve.


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Inyopools  Posted: 06/06/2016 11:26 AM  Inyo Product Specialist

HOTLAP - The pump should be turned on during the RINSE cycle. RINSE for 1-2 minutes. See our guide on "How To Backwash a Pool Sand Filter".

HOTLAP  Posted: 06/04/2016 14:29 PM 

Should I run the pump motor during the rinse cycle or just let the water naturally flow thru, also how long should I rinse?
Thank You

Inyopools  Posted: 05/31/2016 11:08 AM  Inyo Product Specialist

Julie - You may have too much DE in the filter. Try pulling out the grid assembly and cleaning it. Check that the exit ports are not blocked. Only add about 80 % of the normal DE when you reinsert the grid assembly. See if that improves your water flow.

Inyopools  Posted: 05/31/2016 10:43 AM  Inyo Product Specialist

RPQ - This should not have damaged the valve. It just might have dumped some water where you might not have wanted it.

Inyopools  Posted: 05/29/2016 10:36 AM  Inyo Product Specialist

Dannymac – If you have a cartridge filter, it may be clogged up with oils and chemicals even though it looks clean. If the cartridge is 1-2 years old, you might consider replacing it. If you have a sand filter, backwash and rinse it 3-4 times to get any residue out of the sand. If the sand hasn’t been changed in 5 years, replace it.

Julie  Posted: 05/28/2016 21:09 PM 

WE have a Pentair multi port valve for a DE filter, when we backwash very letter water comes out, and a suction forms on the tube the water is suppose to come out of what might be the problem?

RPQ  Posted: 05/28/2016 19:46 PM 

When I started my pool this year I forgot to move from winter setting to filter. I caught it before the water went below the skimmers (probably a half hour). Will this affect my filter?

Dannymac  Posted: 05/24/2016 13:17 PM 

I am having trouble getting my pool clean, I suspected the filter was not filtering correctly, so I put food dye into the basket filter area, half the food dye come out the return during that same pump cycle, I had a look at the spider gasket, and to me it seemed fine, is there anything else I could look at? Thanks

Inyopools  Posted: 05/16/2016 11:26 AM  Inyo Product Specialist

Maureent - I'm not sure what you mean by tapping the multiport valve head off. I would recommend unscrewing the cover assembly - usually 8 screws. Then, lift the cover assembly off to expose the inside of the multiport valve and the spider gasket. Look at the gasket to see if it is damaged. Most multiport valve problems are due to a bad gasket. See our guide on "How to Replace a Spider Gasket on a Multiport Valve". Remember to turn off the pump each time you move the handle to a different mode.

Maureent  Posted: 05/14/2016 8:18 AM 

We have a new multivalve and sand filter but are having problems with water leaking out. We are assuming (by eliminating all other possibilities)that we are getting grit stuck in the multivalve. However we cannot get the multivalve head off. We understood this should only be hand tight but even with gentle tapping it just won't budge. Any ideas please?

Inyopools  Posted: 05/03/2016 11:17 AM  Inyo Product Specialist

Jose - When you replaced the handle, you may have set it on 180 degrees from where it should be. See our guide on "How To Replace a Pool Multiport Valve Handle", Step 9.

Jose  Posted: 05/03/2016 10:23 AM 

Ok... I have an issue. I set it to filter or any other setting for that matter and my pool drains as if it were on waste or back wash. It also pulls all the water out of skimmers completely. Ice replaced web and handle. What could it be

Inyopools  Posted: 04/25/2016 11:08 AM  Inyo Product Specialist

Emy - I am a little confused about your question, but if you are trying to lower the level of water in your pool, you would want to rotate your multiport valve to the "WASTE" position. Make sure you have a hose attached to the "waste" port to take the water away from the pump.

Emy  Posted: 04/23/2016 4:08 AM 

I have a question I want to know the pipe should be on or off because there are three pipes when I lower the level of the water

Inyopools  Posted: 03/26/2016 11:21 AM  Inyo Product Specialist

Terry K - I would recommend buying a vacuum head that attaches to your scrub brush pole and suction cleaner hose. Then manually suction off the white powder with the multiport valve in WASTE mode to keep the powder from going into the filter. You will have to add fresh water when you are done. Here is the link to "vacuum heads".

Terry K.  Posted: 03/24/2016 15:20 PM 

I removed my rhino pool cover today and there was a lot of white DE looking waste sitting on the bottom of our pool. The pool has been covered for the last 3 months.
Question? What's the easiest way to remove the white sediment from the bottom of our pool with or without filter utilization?
When I brush the pool, it cloudy ups the pool water.


Inyopools  Posted: 11/12/2015 14:04 PM  Inyo Product Specialist

wrong MPV - Unfortunately, in many cases, a manufacturer will design the DE MPV much differently than a sand MPV. See our guide on "How a Hayward Sand Multiport Valve Differs from a DE Multiport Valve". If this is your case, the only solution is to replace your current DE MPV with a sand MPV. Not all MPVs are different. Check with your manufacturer before buying another one.

Anonymous  Posted: 11/11/2015 12:18 PM 

We installed a de valve instead ofone for a sand pump. How do we correct this?

Inyopools  Posted: 11/03/2015 17:59 PM  Inyo Product Specialist

motor ran dry - If your system lost prime and your pump ran without water for a period of time, you may have damaged your motor. Without water the pump will run too hot and some of the gaskets and shaft seal may have failed and sprayed water on the motor winding. The motor overload protected may have turned your pump off. Fill your pool and try priming your pump. If it runs, watch for sprays around the pump gaskets and the shaft seal. If you see sprays, turn the pump off and replace all your motor gaskets and seals.

Anonymous  Posted: 11/02/2015 19:51 PM 

I have a question. I left my filter on waste and it rain like that all day. It drained the pool about 2 foot below the skimmer. I am filling back up now. I just wanted to know if I have have messed up my pump or the motor. Please help

wolf380  Posted: 08/28/2015 11:21 AM 

I just purchased a Pentair (was American Multiportvalve) 6 bolt and it is the correct one, however I did not know the O-Ring gasket was not a part of the valve. so now I need a gasket, O-ring and I can not locate it on your web page.

Inyopools  Posted: 08/07/2015 9:15 AM  Inyo Product Specialist

Bueno - Not always. It depends on the manufacturer. See our guide on "How a Hayward Sand Multiport Valve Differs from a DE Multiport Valve".

Bueno  Posted: 08/07/2015 8:48 AM 

Can a mpv for a sand filter be used on a d.e. filter?

Inyopools  Posted: 07/13/2015 13:54 PM  Inyo Product Specialist

FOMBELLBOB - It is possible on some multiport valves to reinstall the rotor 180 degrees out of position, so the modes don't operate properly. See our guide on "How To Replace a Pool Multiport Valve Handle" for an example of how this could happen. If this isn't the problem, you might trying cleaning the grids again to clean out the excessive dirt you filtered out of the pool. Also check the breather tube that goes from the bottom of the filter tank to the top. Make sure it isn't clogged and that the screen at the top of the tube is clear.

FOMBELLBOB  Posted: 07/10/2015 11:05 AM 

I have a nautilus ns36 de filter and a Pentair 1 1/2" multiport valve. we had a bad storm that left a lot of dirt in my pool.After filtering the pool is clean but don't have the sparkle it had before the rain. when I turn off the pool now I get de flowing back in from the suction ive replaced all of the rubber internal in the filter and multi valve and still I get de flowing back in the suction my pool is 24 yrs old and I never had this happen I also replaced the gridS in the filter 2 yrs not sure what is going on.please any suggestion. I was wondering if the rotor was put back in the valve the wrong way and letting a flow go back in the suction when shut off.ALSO I HEAR A GIRGLE SOUND FROM THE FILTER WHEN THE DE IS FLOWING BACK INTO THE POOL.

Inyopools  Posted: 06/23/2015 15:30 PM  Inyo Product Specialist

recirculate - No, the pool would not drain. In recirculate mode the filter is bypassed so you have a straighter line between the pool to pump ports and the pool return ports. Water may move a little when the pump is shut off but it would go back into the pool.

Anonymous  Posted: 06/22/2015 23:13 PM 

If I set my filter to recirculate and the filter timer shuts off the system will it drain the pool?

Inyopools  Posted: 06/19/2015 13:32 PM  Inyo Product Specialist

backwash failure - Check your spider gasket to make sure it is not damaged. Remember to shut your pump off when you move the MPV handle to switch modes, and always push the handle all the way down when you move it. See our guide on "How to Replace a Spider Gasket on a Multiport Valve" for more information.

Inyopools  Posted: 06/19/2015 13:23 PM  Inyo Product Specialist

Stan - The MPV is part of the DE filter. If you are suggesting leaving the DE filter in place and placing a new cartridge filter next to it, I don't see why I think you are saying will not work. With the MPV in "Waste" mode, you would be bypassing the DE filter and going straight into the new cartridge filter. Kind of jerry rigged but I don't see why it wouldn't work.

Anonymous  Posted: 06/19/2015 8:44 AM 

Replaced the multiport valve unit, but now the water doesn't leave the pool during backwash cycle. After running I got the backwash cycle for a few minutes,a suction forms in the incoming line forcing a collapse in the return line

Stan  Posted: 06/19/2015 6:51 AM 

I want to swap my hayward pro grid de with a cartridge filter. It looks like the inlet outlet ports are reversed on the cartridge filter compared to the de. Can I simply connect the new cartridge filter c4030 to the multiport (seems easiest because it's a straight matchup) and simply relate the backwash position as the filter position and be sure to never use the original filter position since that is now backwash?

Inyopools  Posted: 05/31/2015 13:20 PM  Inyo Product Specialist

prime and backwash - Sounds like you may have two problems. Losing prime is a suction side problem - before the or in the pump. You probably have a suction leak in the connections between the pool and the inlet port to the pump. See our guide on "How to Identify and Correct Air Leaks".  Also check an see if you have debris clogging your pump's impeller. See our guide on "How To Clean Out a Pool Pump Impeller". The backwash issue is on the discharge side of the pump and is most likely a damaged spider gasket that needs to be replaced. See our guide on "How to Replace a Spider Gasket on a Multiport Valve" for instructions on replacing the gasket.

Anonymous  Posted: 05/30/2015 17:07 PM 

I replaced the sand in my filter but I can't get the pool to hold the prime. I noticed that when I move to recirculate some water comes comes out through the backwash tube. Are these 2 issues related and how do I fix it?

Inyopools  Posted: 05/17/2015 11:45 AM  Inyo Product Specialist

angie - The only thing I can think of is the unions may have been over-tightened. Please call Hayward at 866-772-2100. They may have other ideas.

angie  Posted: 05/15/2015 17:53 PM 

I have received two Hayward SP0715X62 Pro-Series Vari-Flo Control Valve with Gauge and they have both developed hairline cracks around the pump and return ports within 2 days of installation. They are two different valves and both brand new. We installed them according to specs but still have this problem...please advise.

Lou  Posted: 05/08/2015 15:23 PM 

I thought of that so I emailed Hayward customer service. He told me the same thing. The ports are reversed so he sent me a label to put on the new assembly to align with the ports for a DE filter application. I took a closer look at the old assembly for the DE filter. It is very worn and I wonder how it lasted this long. Hopefully with the new assembly, the handle will turn much easier. It never turned easy and I thought this was normal not having any experience with pools before. I guess you live and learn.

Inyopools  Posted: 05/07/2015 17:09 PM  Inyo Product Specialist

Lou - DE Multiport valves are sometimes different from sand Multiport valves. There ports are reversed. You would be safe using this assembly for the sand filter MPV.

Lou  Posted: 05/06/2015 13:39 PM 

Thank you for the information on replacing the spring and bearing. I decided after reading the instructions on how to do this not to attempt the repair. The valve is at least 13 years old and I'm sure other things will need replacing (I'm not the original owner of this). Instead I decided to order a new handle and cover assembly. The only other question I have is what is the difference between this part for a DE filter vs. a sand filter?

Thank you for your help.

Inyopools  Posted: 05/06/2015 9:52 AM  Inyo Product Specialist

Lou - Sounds like the non-metallic bearing is your problem. If it is broken, it will interfere with the rotation of the handle. See our guide on "How To Replace a Pool Multiport Valve Spring" for information on how to get to that bearing.

Lou  Posted: 05/05/2015 18:51 PM 

The handle has always been hard to turn and makes creaking noises when it is moved. With the replacement of the spider gasket it got worse. When I push it down all the way there is still rubbing and very hard to turn. It looks like the non-metallic bearing is broken in the middle and not providing the pivot action needed. This being the case, should I replace the bearing since a new one came with the rebuild kit. Or buy a new assembly which has the handle, bearing, cover plate, spring, and cone? This would be SPX0715BA3.