How a Multiport Valve Operates

Written by:  Danny Rhodehamel
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 (3.86 OUT OF 5 STARS ON 24 RATINGS)

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.

Tips & Warnings

Video

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.

Comments (41 to 80 of 187)

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User: Shauna

I have a Jacuzzi laser sand filter and for some reason it seems to not be filtering through the sand or is improperly being diverted straight back into the pool when we put it on filter it completely stops all water flow back to the pool but if we push down on the dial it flows but still does not flow through the sand, we have put shock in the skimmer and it shoots straight back out through the filter into the pool. We are new to sand filters and have no idea what could be the cause of this if someone could help and tell us how to get the water to divert through the sand and back to the pool the proper way it would be of great help to us, thank you

User: Inyopools

Cloudy water - If you haven't changed your sand for 10 yrs, you should do that now. Sand, or its equivalent, only lasts 5-7 years. Most sand filter owners use the pool sand that you can buy at a local hardware store. And you should fill it to within 6" of the top of the filter tank. See our guide on “How To Change Sand In a Sand Filter” for further information.

User: 

hi i have a hayward sand filter 24" dia X 34 tall. it s 10 yrs old. i cannot keep the water from being cloudy. the chemicals are fine. is it time for me to change the sand ? if i remember right the instructions had me install a very small pebble type media. Could you tell me do u think this is the possible problem and what type of media/ sand should i replace with and how much ? the multi port valve seems to be working fine .. thankyou

User: Inyopools

Sarah - There are generally two plugs at the bottom of a pump either of which could be used to drain the pump. See Step 2 of this link for a picture of where they are: "How To Measure Total Dynamic Head With Gauges".

User: Sarah

My in ground pool/pump is broken and not working. Is there any way for me to drain water out of it while the pump wont work?

User: Inyopools

bella81762 - You could check to make sure your spider gasket in your MPV is not leaking water between the ports, but I don't think this is your problem. Your problem is probably due to a chemical imbalance. We have several guides on correcting an imbalance. See our guides under "Pool Maintenance" for more information.

User: bella81762

hi, i have a hayward filter, and i cannot keep my water clean,,i have been floccing,, and vacuming,to waste it clears and 2 days later is cloudy again, have had the chemicals checked at the store,,,they are perfect, changed the sand, while the body is new,, the hayward variflo, is rather old...is it possible, that for whatever reason maybe the water is not going thru the sand,,,and i need to replace the valve,,,

User: Inyopools

cjames - You may have a damaged spider valve that needs to be replaced. See our guide on "How to Replace a Spider Gasket on a Multiport Valve" for further instructions.

User: cjames

Im new to using a sand filter with a dial top and just bought a used Sand Dollar sand filter. Unable to keep dirty water from coming back into the pool when vac. pool...even when it is in the waste position. PLEASE HELP!!!!

User: Inyopools

Daryl - You are correct. "Drain" is the same as "Waste". "Whirlpool" = "Recirculate". This setting bypasses the filter. And "Test" used with AG pools, blocks the filter and stops the water from coming back into the pump.

User: Daryl

First of all, thank you for this site. Is a great tool for us pool owners that don't get good advice from our local pool store. I have a Jacuzzi MFM filter and the valve settings are different from what I've seen on your site. I have filter, backwash, rinse and winterize. But th there's whirlpopol, drain and test. I'm assuming that drain would be waste, and whirlpool would be filter bypass. I guess test would be closed. Is this right?

User: Inyopools

RBW - You may have a damaged spider gasket. Its purpose is to help separate the flow of water between the multiport valve ports. The gasket for your SP710XR50 valve is: "Gasket, Valve Seat - 5 Spoke (spx0710xd)". See our guide on "How to Replace a Spider Gasket on a Multiport Valve".

User: RBW

I have a Hayward Proseries DE filter with 6 multiport SP710XR50. Debris has been recirculating back into the pool. I backwashed and dismantled the filter and manually cleaned out the grid system (which was replaced last year). The problem still occurs, in fact its getting worse. Do I need to replace the multiport system or is there a simple solution to this?

User: Inyopools

HRKIII - Sound like your Key Assembly is broken. Unscrew the 6 screws on top of the valve and remove the top assembly. You should be able to see the Key Assembly and see what's wrong. See our guide on How To Replace a Pool Multiport Valve Spring for instructions on replacing the key assembly.

User: Inyopools

jw - If the sides of the channels holding the gasket are worn down, you may be getting sand transfer. You may have to replace the key assembly. If you recently changed your sand, you may be getting fine sand into your pool that is not being filtered. Try rinsing your sand a couple of more times to clear out the fine sand and repack the rest. Vacuum off the sand at the bottom of the pool in waste mode so that it doesn't keep recycling.

User: HRKIII

Last night after I backwashed my filter I pushed the lever to switch to rinse but the lever would no longer switch modes. It feels like it is just free spinning inside. Do I need to replace the entire housing? (SP714T)

User: jw

have hayward sand filter past year getting sand in pool ,took filter apart laterals and stem are fine no cracks anywhere ,multi flo valve where spider gasket goes is worn can this cause sand to enter pool

User: Inyopools

pool lady - Here's a link to our guide on "Installing a Pool Sand Filter". See Step 24. It show a picture of the common Hayward Multiport Valve label. Click on the picture to expand it. Hayward no longer sells just the label.

User: Inyopools

Monique - I don't understand how the rinse water can be "really dirty" if you just changed the sand. Hard to tell what's wrong from the description. You may have to pull the sand out of the filter again and check that the laterals were not clogged in the change process. Also check that your spider gasket didn't get damaged in the process.

User: Inyopools

samosia - Unfortunately we do not carry the Pantera II sand filters, but here is a link to the manufacture's website: Onga Pantera High Rate Sand Filter sold through Pentair. Click on the Pantera Series II prompts for product information and owner's manual If you need more information, give Pentair a call at 1-800-831-7133.

User: pool lady

I have an older Hayward sand filter and the label is totally gone. where can I get another one? or at least see it online.

User: Monique

I have a Hayward ESeries sand filter, changed the sand, changed the spider gasket, examined finger laterals. Pressure is fine, pool water stays cloudy, chemicals fine. Backwash line was leaking on filter mode but then stopped leaking, when I backwash water just barely comes out, when I rinse there is more water that comes out but it's really dirty.

User: samosia

I have an older Pantera II sand filter and the label has been removed. The previous owners used a marker to indicate where each setting is but it doesn't match with the new replacement label that I recently picked up. It seems that the filter and backwash are in the same place but even those two I'm not 100% sure of. Any way to differentiate between the waste and backwash and the recirculate and filter?

User: Inyopools

KrisM - If you have water flowing where it shouldn't be, it still sounds like you have a bad spider gasket. Recheck your gasket for flat spots or small tears. Then check to see if you have any cracks in the valve itself. Also check that you don't have a weak spring under the handle. A weak spring could allow water to pass over the gasket.

User: KrisM

Cant clear my cloudy pool. All chemical levels are in ideal range. When I backwash some water still goes into the pool. When I vacuum some dirt goes into the pool. Opened the valve to look at the spider gasket, looks ok. Do I need a new valve? Can't tell if the valve is seating properly in the right spot. How do I tell?

User: Inyopools

backwash leaking - Sounds like your multiport valve spider gasket is blown and will have to be replaced. See our guide on "How to Replace a Spider Gasket on a Multiport Valve".

User: 

i get water out my backwash port when in filter mode is the head bad ? do i need a new head ? can i rebuild head?

User: Inyopools

Jason - The only difference between your filter setting and rinse is where the water is being discharged - filter goes out the return port to the pool. Rinse goes out through the waste line. If Filter works well, than we know that the filter and valve are working up to the discharge ports. If neither rinse nor backwash works, that would imply that something is wrong with the waste port. Is there anything blocking the waste line?

User: Jason

I put a new multiport valve on our pool. It has plenty of pressure when filtering, but when backwashing and rinsing the water is just barely coming out the waste line. If I push the handle down while it is set on backwash it pumps better but still not as good as last season. As soon as I let the handle go it looses pressure again. Up until this year it worked fine, it would backwash and rinse with enough pressure that it looked like a fire hose. It started doing it with the original valve, so I bought a new one thinking it might be seals going bad, but the new one isn't working any better. Any idea what may be causing it?

User: Inyopools

Guy C - I'm not sure what you what to do but I think the answer to your question is no. You cannot use the multiport valve to divert water to the solar panels. The return port eventually goes back to the pool. You could have it goes to the solar panels from the filter. In recirculate mode the valve would bypass the filter, but when you put the valve in filter mode the water would still go to the solar panels. Usually people put in a pair of diverter valves after the filter to direct the water to the solar panels or to bypass the panels and go directly to the pool.

User: Guy C

Can I use the re-circulate setting on my filter to divert water to a solar heater ? Will this work

User: Inyopools

debi - If you have a side mounted valve, check to see if the air relief tube inside the tank is clogged. It runs from top to bottom to relieve pressure at the top of the tank. Check to see if your motor's impeller is clogged. See our How To Guide. If you have very dirty water, it may be clogging your filter. When initially cleaning, dump the dirty water from the bottom of the pool, out the waste port.

User: Inyopools

mary - Generally you cannot use any kind of multiport valve on a Triton filter. The spacing between the input and output ports vary between filters.

User: debi

I have a sand filter and have had it about 4 years. When I first started it up it did not sound right when I shut it off, water shot back thru the skimmer basket about 2 feet high. I finally got it going but when I tried to clean the bottom it will run a few minutes and lose suction. I changed the sand out and check all tubes which look fine. I have not water leaks but I can not figure out what to do to not lose suction.

User: Inyopools

homeboy - You may have installed a pump that was stronger than your old pump. A pump's real Total Horsepower (THP) is equal to the HP on the motor label times the Service Factor (SF) on the label. Compare the THP of your old motor with the one of your new motor. Pressure gauges do go bad. Try swapping out yours with a neighbor's to see if you need a new one. Finally, the small leak in the pipe between the pump and the filter will not cause your water pressure to go up. If anything, it would relieve some of the pressure.

User: Inyopools

mison2014 - We do sell the valve body only. However the cost of the body is almost equal to the cost of the whole valve. At this point, I would replace the whole valve.Click on underlined items for more details and prices.

User: mary

Can I use any kind of multiport valve on a Triton filter as long as the fittings are the correct size?

User: homeboy

I just installed a new Hayward pool pump in my inground swimming pool and the pressure guage seems to be high (20 - 23 PSI). It was only between 16 and 20 PSI with old pump. Also my pressure guage go to 3 when the pump is turmed off and have a small leak in the pipe ging into the sand filter. Is the pressure guage broke or can the small leak be causing this problem.

User: mison2014

I have a Hayward DE4820 filter with a Hayward Sp715XR50 vari flo valve. I only use filter, Backwash, Rinse and waste. The body has a crack so I must replace. Is there another valve I can replace it with?
Or do you sell only the body for this valve. the controller top is in great shape as i replaced it about 4 years ago.

User: Inyopools

Stones - Leaking out the waste port while filtering is generally caused by a damaged spider gasket. See our How To Guide on Replacing a Spider Gasket. Typical psi while filtering is 10-15 psi.

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Tips & Warnings

Continue backwashing until the water shows clear in the sight glass on the side of the valve.

Don't backwash excessively. Contaminates in the sand actually help the filter work more effectively - to a point. Monitor your pressure gauge for an 8-10 psi rise.

Never move the valve handle when the pump is on.

Don't vacuum your pool in backwash mode. You may clog the collection pipes (laterals) at the bottom of the filter.


Please Note:

Inyo Pool Products is not responsible for any injury or damaged equipment
while using our guides. Using our guides is doing so at your own risk.
These guides are suggested use of your pool or spa equipment and may vary
depending on which product you are using.