Plumbing, Heating and Pool Repair Guides

Sand Pool Filter Troubleshooting & Repair Guide


The sand style swimming pool filter can be found on many above ground and in ground swimming pools. There are also many different brands and models of swimming pool filters on the market these days so all the parts will not be interchangeable but many of the things you will need to repair on any sand filter will done basically the same way. The difference between most sand filters is size and brand. Most sand filters these days are equipped with multi-directional flow valves also known as multi-port valves.Sand Pool Filter Troubleshooting & Repair Guide

Common repairs like replacing the multi-port directional valve, changing the sand inside of the filter, replacing broken laterals and you will need to learn how drain the filter for winterization and for these repairs listed. Knowing how to properly repair and troubleshoot your sand swimming pool filter can save you a lot of money and time in the long run, leaving you to spend that time enjoying the pool rather then working or spending money on it.

The Swimming pools sand filter troubleshooting and repair guide below will help you diagnose and repair the most common problems on almost all brands of sand filters. You can repair your sand filter with a basic socket set and some standard hand tools. Always be sure to only work on your swimming pool filter when the filter system is off. It is also a good idea to shut the pool timer and disconnect the pump from the power source if possible when working on the filter. This will prevent the pump from kicking on when you are working on the filter.

How To Change The Pool Filter Sand

Pool Filter Sand
If your sand is getting old in your sand filter you are going to have to replace the sand. To replace the sand in your swimming pool filter you will first have to shut the filter system off. Once the filter is off you will have to either start unbolting the bolts around the center of the filter tank, which is most common on older Hayward S-series sand filters. If you have a newer sand filter or one with the multi-directional valve called the multi-port on top of the filter you will want to remove the band that clamps around the base of the multi-port.

Now that you have the filter tank open and you can see the filter sand, you can remove the sand three different ways. The first way is to take a small plastic scoop and manually scoop all the sand from the filter. If you have a large sized sand filter this took take a while. The second way you could remove the sand from the pool filter is to lay the sand filter on its side and dump the sand out. This will normally only be able to done with smaller sand filters like the Hayward S-160 models since they are smaller.

If you do not find any of the two methods above to be something that you can do then you can use the third way of removing the sand from the sand filter. You can use something called a swimming pool filter sand vacuum. This is a special vacuum that is made to connect to a garden hose and create a Venturi effect and will suck all the sand out of your pool filter. This is by far the best and easiest way to remove sand from pool filters.

How To Drain The Sand Filter Tank

If you need to winterize or change the sand in your swimming pool filter you will need to know how to drain the filter tank correctly. What you will want to do is to look around the base of the sand filter tank for the drain plug or screw. On Hayward S-Series models the drain plug with be a white or black cap that will almost resemble a soda cap. Turn the cap to the left until it screws all the way off the threads and then remove it. Open the air bleed screw on top of the filter dome to allow some air into the filter so it can drain better.

On other models of pool filters the drain plug will be located somewhere on the bottom of the tank. On Sta-rite sand filters you can find the drain plug in the center of the bottom of the filter tank. The drain plug will be white and around 2″ inches in outer diameter size. Oh Pentair Filters you will see the drain plug either underneath or on the side of the tank.

Hayward Sand Pool Filter

How To Add The New Sand To The Pool Filter

Once you have emptied all of the old sand from your filter you are going to have to add new sand. Before you add the new sand you will want to inspect all the filter laterals to make sure they are not damaged. Sometimes the laterals will crack from age and when then do they can allow sand to bypass them, which will result in you having sand return into your pool. Once you have inspected all the laterals and they all look OK you are going to want to fill the filter tank up with some water. You will want to fill the tank with water to about 4″ above the laterals. This is to protect the laterals when you start to pour the new sand in.

Once you have the water in the tank the last thing you will want to do is to put something over the manifold pipe that will be sticking straight up in the filter tank. A plastic cup or laying an old rag over the opening of the pipe will prevent sand from entering. Once you have done those two things you can now start to pour the amount of sand you need into the filter. Once all the sand is added to the filter tank you will to reassemble the filter.

How To Change Sand Filter Laterals

If you are getting sand back into your swimming pool and you have a sand filter then chances are your laterals are bad. Laterals can be found on the bottom of the filter tank. Their job is to allow water to flow through the sand and the filter but to keep the sand inside of the filter tank at the same time. The laterals are just small tubes that have slits in them that allow the water to pass through. You will find them connected to the bottom of the filter collector or manifold pipe that runs vertically in the center of the filter tank.

From time to time these laterals will break from a number of reasons and you will start to get filter sand back into your pool. To change the laterals you will have to shut the filter system down and drain the filter tank. You then will have to remove the multi-port or unbolt the filter tank so you can then remove all of the sand.

Once you remove all of the sand from the filter tank you can remove the laterals and the manifold assembly from the filter tank. To replace the filter laterals you will either have to replace the entire lateral manifold system unless your laterals unscrew from the manifold. On some model sand filters the laterals will unscrew from the manifold near the base. If you have tried to un-spin the laterals and they do not move you will have to replace the entire lateral assembly.

Once you have changed the laterals and replaced them with new ones you will want to fill the filter tank up at least 1/3 of the way and then pour new pool filter sand into the tank. Once you have the new sand in the tank reassemble the rest of the filter, which will include the multi-port and anything else you removed while working on the filter. Next you will want to run your swimming pool filter when everything is all back together to make sure there is no leaks or sand returning back into your pool.

Testing The Sand Pool Filter After Replacing The Sand

Once you have everything all back together you will want to prime your swimming pool pump and get your filter system going. You will want to make sure that the belly bands and multi-port gaskets are not leaking. You will also want to backwash the new sand for a few minutes as well to wash small debris off of the sand that might have been mixed in while the sand was being added to the filter. After you have back washed the new sand for a few minutes you will want to run the filter for a few minutes to make sure everything is OK while walking to the pool to make sure that you are getting no sand back into the pool. If everything looks good you will want to run your sand filter for 6 – 8 hours a day depending on weather conditions and how much the swimming pool is used. Make sure to always backwash your sand filter once a week.


  1. My skimmers only work if a open either the drain valve or hoover valve and these is no debris in my filter basket or skimmer baskets

  2. I changed sand recently and I have a slow flow at the skimmer and when I shut the pump off it takes some time before the pump regains the water and jets flow. I had neither of these problems for six years. Anyone know what I did or what could be wrong??

  3. HELP. Have been getting a lot of sand in my pool. Changed all the laterals and checked the manifold pipe and found no leaks. Restarted the filter and the sand has already started to accumulate on the bottom. What else could it be?????

    • I had the same problem today. I disassembled my unit and removed the sand to find the plastic pipe leading from the laterials to the filter head broken.

    • The spider valve has probably jumed its track you can unscrew the top of the sand filter and replace it or you can add a ball valve to your drainpipe and just remember to open it when you use the backwash .

  4. we had to add a bag of sand to our filter and they gave us a different kind of sand so there are two different kinds since adding the sand our water presser seems to slow down after the pool has been running for a while ! why is this happening >

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