System with a sidemount multiport valve and a sand filterThe multi-port valve on your swimming pool is an important component of your swimming pool system. We get a lot of frequently asked questions about the multi-port valve. Please feel free to add yours below if we don’t cover it here.

The multi-port itself does not have a power source. Water flows into the pump from the main drain and returns of the pool, is pumped up and into the multi-port valve. The valve is just that, a multiple porting valve for the water. Typically you have several options for operation of your multi-port, they tend to be filter, backwash, rinse, winterize, drain/waste, and recirculate/whirlpool (names may vary based on manufacturer). The job of the multiport is simply to tell your water where you want it to go.

The filter setting is obvious. The multiport will tell the water to go into the top of your filter, travel down through the sand (in a sand filter) or in and through the de of your de filter, and then the water gets fed back through the outlet pipe of the filter and into the heater, finally back into the swimming pool.

System with a top mounted multiport valve and sand filter

The backwash setting reverses the flow of the water. Instead of going in through the top of the filter and down through the sand, the water goes in through the bottom, pushing the water up through the sand, lifting debris off the top and pushing them out the waste hose.

The rinse function reverses the flow back to normal filter flow, with one exception, it continues to put the water through the waste hose to clean out any leftover debris in your pipes. If you turn the water back on to filter, and your pool returns are showing a fine mist of dust /dirt/debris back into the pool either you didn’t backwash long enough, you didn’t rinse long enough, or something is broken.

The recirculate setting on your multiport valve will take the water in through the pump, put it through the multiport valve, bypass the filter, and put the water into the heater/return jets to the pool. This is a setting that can be used to troubleshoot filter issues, and help your pump gain prime more quickly than it sometimes will if you have recently opened your system to introduce air into the lines.

The waste function on the multiport valve takes the water in to the valve and puts it directly out your waste hose. This is a nice setting if you are vacuuming debris from the bottom of the pool and you don’t want to clog up your filter, or the particles are too small to be effectively filtered. This setting can also be used to simply drain excess water from your pool. If you do use the waste setting to vacuum, you will most likely need to add water to your pool, as the size of your plumbing dictates how much water is coming out, and it can be substantial – depending on how long your run it on this setting.

The handle on your multiport valve should move freely when pushed – however, NEVER try to move the handle while your system is running. The water pressure running through your system is very strong. If you attempt to move the multiport handle while the water is running it can break things within the multiport and cause any number of problems. One of the most common issues if this happens is your spider gasket, that seals the top and bottom of the multiport together can be pushed out of position, causing malfunctions in your valve. If the gasket is out of position, it can misdirect water into more than one place at a time while running. The multiport can typically be taken apart to assess the condition of the inner parts. When it looks like it should be replace, make sure you do this. It’s a relatively inexpensive part, and plays a large role in your equipment.

The multiport itself does not have a power source, and it should not make noise. If you are trying to troubleshoot a noise, unless it is an airleak, or a misdirection of water, the noise is most likely coming from somewhere else.

The multiport valve commonly has a plug, a pressure gauge is sometimes attached to the valve (unless you have a system where the pressure gauge is mounted to the filter) and a sight glass. These parts are taken off for proper winterization of your equipment and reinstalled during your opening. If you experience a water leak from any of these areas, you may want to take out the part, put some magic lube (water based lubricant) or teflon tape on the threads to prevent leaking. A drip every once in a while is okay. A stream, depending on how much water is involved is something that should be looked at.

Sometimes a system is installed with a filter and multiport that are side mounted, meaning the multiport is next to the filter (on the side). Other times it is a top mounted multiport, meaning that the multiport valve is on top of the filter.

If your handle or any part of your multiport malfunctions, please call your pool professional. We are happy to troubleshoot and help you replace your valve if needed. We also offer lessons for proper pool operation, so just ask!