Pool Filter Settings Explained – Pool Multiport Valve Guide

The many pool filter settings on a multiport valve of a swimming pool sand filter can be pretty confusing when you first get a pool. But, like most things, it is pretty simple once you know. You will soon understand what all of the pool filter valve positions mean.

There are normally 6 different pool filter settings on a multiport valve (MPV) which are:

• Filter
• Backwash
• Waste
• Rinse
• Recirculate
• Closed

Some valves also have an additional 7th position which is Winterize.

I will go through what all the pool filter valve positions mean in turn and explain what each does.

Table of Contents

• Pool filter valve positions
• Backwash vs waste – what is the difference?
• Pool Maintenance Course
• Inside a pool multiport valve
• Multiport valve problems
• Multiport valve (MPV) mounting positions
• Other types of filters and valves
• Pool filter settings Youtube video
• FAQs

Pool filter valve positions

Filter Setting

The filter setting is used to filter the pool water through the sand. It is the pool filter valve position your pool filter valve will spend most of its life on. Mostly it will be used when the pump runs on your timer to keep the water in the pool clean by flowing through the filter media.

The filter setting is also the normal pool filtration setting you will use the most when vacuuming your pool. Whenever the dirt levels are not too high you can let the filter remove it and then backwash to eject it from the system. My article “How to clean dirt from the bottom of a pool” explains this process fully in a step-by-step guide.

When the multiport valve handle is on the filter setting, and the pump is running, the water will be drawn into the system through the skimmers and bottom inlet (if you have one). It will then pass through the debris filter basket on the inlet side of the pump so that any large pieces of dirt, such as leaves, will be removed prior to passing through the pump as they could cause damage. The water then travels through the pump and into the top of the sand filter.

Here the magic happens. The water passes through the sand which traps any small particles of dust and other dirt. When the water reaches the bottom of the filter it returns to the pool as clean water through the inlet jets, waterfall or whatever other similar feature you may have.

Backwash setting

You use the backwash setting to clean the sand in the filter, often immediately after you vacuum the pool or when the pressure on the pressure gauge is high.

The backwash setting will be the multiport valve position you will use the second most frequently, after the filter setting.

It works by the pool water being redirected the reverse way through the sand filter. So after leaving the pump it goes into the bottom of the filter and travels up through the sand, dislodging the dirt and debris as it goes. The water containing the debris then goes to the waste pipework and out of the system.

For a full guide to backwashing my article “How to backwash a pool – step by step” will explain everything.

Waste setting

Many people seem to get confused about what is the waste setting on a pool filter used for.

The waste setting on the pool filter is used, in the following three situations:

1. When you wish to reduce the amount of water in the pool, perhaps after heavy rain or even to empty the pool fully.
2. When your pool is very dirty you would vacuum on the waste setting so the dirt goes straight out of the system without passing through the filter. That way it doesn’t clog up the filter.
3. If you have a heavy infestation of algae then often the tiny particles won’t get trapped in the filter so will go straight back into the pool. Vacuuming on waste means it will be ejected out of the waste pipe and will not reenter the pool.

On the pool filter waste setting the pool water will be drawn into the system and then pass through the debris filter basket on the inlet side of the pump. From there it is expelled from the system without passing through the filter via the waste pipe.

Where the waste water goes depends on your system. It will either be sent straight into the sewer system or out into your yard/garden, often through a roll-out waste hose so you can direct the water to an area of the garden you want.

Sometimes Waste is labeled as “Pump to Waste” on some multiport valves.

Rinse setting

What does rinse do on a pool filter is probably the most misunderstood setting.

The pool filter rinse setting is used after backwashing the sand filter and it is used to clean the sand or other filter medium in the filter housing.

In the rinse position, the water travels in the normal direction through the sand and can remove a few remaining particles of dirt but its main function is to settle the sand filter bed back down ready for the filter to work. You normally run the pool pump for between 30 seconds and one minute on the rinse setting.

The pool water goes to waste when on the rinse setting and not back into the swimming pool.

If you don’t use the rinse setting after backwashing the sand filter then it is likely that when you restart on the filter position you will briefly get a cloud of dirty water out of your return jets while the sand settles down again.

Sometimes Rinse is labeled as “Filter to Waste” on some multiport valves.

Closed setting

The closed setting shuts off all water flow. It can be used for the following two reasons:

• If your pool will not be used for some time, perhaps if it is empty or during the winter.
• When you want to empty the strainer basket that traps leaves etc before the water enters the pump.

To do this you close the valves from the skimmers and other inlets and then set the valve to closed. You can then remove the see-through lid from the basket housing and empty it without air running back through the system which could give an airlock, something you want to avoid. Once you have emptied the strainer basket and you have replaced it and screwed on the lid then the valves can be opened.

Recirculate setting

Of all the pool filter valve positions, the recirculate pool pump setting is probably the one you will use the least. Actually what does recirculate do on a pool filter is one of the most frequently asked questions I see on the various pool forums from new pool owners.

In the recirculate setting the water is drawn in through the skimmers as normal and, after passing through the pump, goes straight back into the pool via the inlet jets, waterfall etc without passing through the filter.

The only time I have ever used recirculate is after I gave my pool a very strong shock and wanted to mix the shock around the pool without it being absorbed by the filter.

Winterize setting

Not every multiport valve has this setting, although it will normally exist where the pool is located outside in a cold climate. It is generally found between the closed and the waste setting.

Generally it does not allow the handle to fully go down in this setting. It is designed to allow the water to expand a bit without damaging the valve should the water freeze.

Backwash vs waste – what is the difference?

It is easy to get confused as with the pool selector valve in either position water is expelled from the pool down the waste pipe.

The difference between backwash and waste is that in the backwash position, pool water passes through the sand filter backward removing any dirt or debris trapped in the sand before going down the waste pipe. In the waste setting the filter is bypassed so the water passes straight out of the waste pipe.

IMPORTANT
Never operate the selector lever on the multiport valve with the pool pump running.
This can cause severe damage to the valve so always turn the pump off first.

Pool Maintenance Course

When I first bought my house with a swimming pool, I knew nothing about cleaning and maintaining it. I was recommended Swim University’s Pool Care Handbook and video course so I bought it and have never regretted it.

It was probably the best money I spent that year as I have saved thousands by doing it myself.

Inside a pool multiport valve

When you push the multiport valve handle down and move it the light-colored unit on the right of the photo turns allowing water from the pool pump to pass through the opening into whichever of the sections in the bottom of the valve housing on the left side of the photo that the hole lines up with.

Multiport valve problems

Stiff selector handle

Occasionally you may find that it becomes more difficult to push the handle down and turn it to select a different setting. This is easy to rectify.

First, you can try squirting some penetrating oil around the base of the handle and then moving the valve to allow the oil to lubricate it.

If this doesn’t work, you can remove the handle quite easily by pushing out the retaining pin in the side of the handle and then removing the handle so that you can properly lubricate the shaft it is attached to.

Water leak from the side of the housing

I have had this problem. The most likely cause is that the o-ring that is mounted inside the valve body top cover is allowing water to seep out. This may be because it is either not aligned correctly, it is broken or it requires lubricating.

To remove the top cover, switch off the pump then remove the selector handle (see above). The top cover should just twist and then be lifted off. There may be a small (often white) plastic retaining lug along the side of the top cover that you need to remove by lifting it up. Some top covers have retaining screws that need to be removed.

You will then see the o-ring which will locate along the top of the bottom housing. Inspect the o-ring for damage and also look for cracks in the housing.

If it looks ok and fits properly then use some Hayward Jacks Multilube (available on Amazon) or something similar to lubricate the o-ring to make a better seal. Replace the o-ring and then reassemble the housing and handle.

Multiport valve (MPV) mounting positions

There are two positions in a pool filtration system where an MPV may be installed. In either position, they operate in the same way.

Top mounted MPV

A top mount multiport valve is quite common, particularly on smaller sand filters. The MPV is located directly on top of the sand filter tank housing. This position requires less plumbing than a side mounted MPV.

Side mounted MPV

Side mounted MPVs are often used on larger sand filters and DE filters. If they were mounted on the top of a larger filter tank housing it would make them quite tall so harder to place inside a pool equipment housing.

Other types of filters and valves

DE (Diatomaceous Earth) filters

These generally have a multiport valve the same as you find on a sand filter system. So everything written above also applies to a DE filter system. DE filters are not backwashed as frequently as sand filters generally.

Cartridge filters

Cartridge filters do not use multiport valves as they do not require backwashing or rinsing. To clean the filter it is removed and cleaned manually or replaced with a new one.

Slide valves

On some sand and DE filter systems a series of slide valves are fitted instead of a single multiport valve. Opening and closing the valves in a particular combination gives the required settings for backwashing, filtering etc.

Pool filter settings Youtube video

You may wish to watch my video on what do the pool filter valve positions mean below. You can subscribe to my Youtube channel here.

FAQs

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