No Suction in Pool Skimmer? This Is What to Check

Whether you have an above ground pool or an in ground pool, having debris and bugs floating around on the pool surface is not nice for swimmers. If you constantly have this then it is likely that you will find that the pool’s skimmer is not working properly so you need to investigate.

There are a number of things that could result in your swimming pool skimmer not working, or at least not working properly. Most things are easily fixed by pool owners, fortunately.

If your pool skimmer is not skimming it will generally be for one of three reasons:

• the level of water in your swimming pool is too low (or too high)
• you are getting no suction in pool skimmer so it is not pulling debris in
• you have a problem with the weir door/flap in your skimmers so that debris is not being trapped in the skimmer

As well as the skimmer not working well, having this problem may also affect how your automatic pool cleaner or manual pool vacuum operates.

I will go through the various options to try and solve the problem of a pool skimmer not working well to help you identify the problem.

1. Is the pool water level correct?

The first thing to look at, if you find your pool skimmer is not skimming, is the water level.

Is it correct?

The water surface level should be roughly halfway or a little more up the skimmer inlet hole.

Level too low

If it is much lower than this, or perhaps doesn’t even reach the skimmer inlet then that is the problem. To rectify it you need to raise the pool’s water level by topping up with a hose pipe.

If you have an automatic top up system then lift the lid and check that the float has not become caught in an upward position, which would mean the valve was not opening to let water in. If it is free then check that when you push the float down that water starts to come in.

Level too high

If the water level in your pool is too high, so it comes right up to the top of the pool skimmer hole, or even above it, then the pool skimmers cannot function correctly.

The most common reasons this may occur are if you have had some heavy rain that has raised the level of the pool or, if you have an automatic pool top up, there may be a problem with the float getting stuck so the valve continues to open letting water into the pool or it could just be badly adjusted.

To rectify it you need to pump out the excess water using the waste setting on the multiport valve until the water level is correct (after fixing the problem with the pool top up if that is what caused it). See my article What do the settings on a multiport valve mean if you are unsure.

2. Pool pump not pulling water from skimmer

If the water level in the swimming pool is correct then you need to determine whether you are getting suction in your pool skimmer or pool skimmers. The pool pump not pulling water from the skimmer causing no suction is a probable reason if your pool skimmer is not pulling debris in.

With the pool pump running on the filter setting, can you see water being drawn into the skimmers? If you can’t see water coming in then try putting a hand over the inlet port at the bottom of the skimmer. Do you feel any suction? If you cannot, so you have no suction in the skimmer, then it means the pool pump is not pulling water from the skimmer so you need to investigate further.

If you have plenty of suction but debris floating on the surface is not being drawn in, or the debris doesn’t stay in, then it is probably a problem with the skimmer weir. See next section.

If it seems like the pool pump not pulling water from skimmer then check the following things. Most of these should be part of your regular pool maintenance.

Is the skimmer valve closed?

This is an obvious one but it can be easily overlooked. Check that the flow control valve in the pipe that draws water from the pool skimmer to the pool pump is open and not closed, or just partially open.

If you have too much water being drawn into the system from the main drain, rather than the skimmers this could be the problem, so try closing this and see if the skimmer suction increases.

See my post Should the main drain be open or closed?

Is the skimmer basket blocked?

Check that the skimmer basket, or skimmer baskets if you have more than one skimmer, is not full and blocked by debris (leaves, bugs, pollen etc). If it is then it will prevent the pool skimmer from working so empty it, replace it and see if you have suction now.

Is the pump strainer basket blocked?

Check that the pool pump strainer basket is not full of debris. If it is then it will stop the proper flow of water to the pump. If it is full of debris then to empty it without getting an airlock follow these instructions – How to empty the pool pump strainer basket without getting an airlock.

Does the filter need backwashing?

Your pool’s filtration system needs regular attention to ensure it works properly, which includes backwashing or removing cartridge filters to clean them.

Sand filter (or DE)

You may have little suction if the sand filter needs backwashing as debris trapped in it will be reducing the flow of water through the pool filter. You can look at the pressure gauge to see if this is particularly high, in which case backwashing is definitely required.

Read my article How to backwash a pool if you are unfamiliar with this.

Cartridge Filter

If your pool’s filtration system has a cartridge filter then it may be clogged and need cleaning.

Stuck pool float valve assembly

In some skimmers (with two holes at the bottom) you may have a pool float valve assembly. These can get stuck so that water is being drawn from the equalizer line/main drain rather than from the skimmer itself. You should remove it and check that the float is moving freely.

In fact, just removing it and running the pool pump will show if that is the problem as you will notice an increased flow into the skimmer if the valve was stuck.

To find out more read my post – should both holes in my skimmer be open

Is there an airlock?

You may have an airlock in the system which is preventing the swimming pool circulation from operating correctly. Often this can be because there is air trapped in the pool filter housing which needs bleeding.

Read my article How to bleed air from a pool pump or filter.

You may have a blockage

If all the above are ok then you may have a blockage in the pipes going from your pool skimmer to the pump. With the pump off you can try using a garden hose to push water back from the pump to try and unblock it (if that is the problem).

With the pool pump off, remove the pump lid, take out the pump basket and push the garden hose into the inlet side (ie away from the pump) as far as you can get it. Then turn on the hose to start the water flowing.

If you can see water flowing into the pool skimmer from the bottom then you have no blockage. so it is not a clogged skimmer line.

If you have a blockage you will probably see debris coming up from the skimmer inlet.

Collapsed flexible skimmer pipes perhaps

If all else fails you may have a blockage in the skimmer line but not due to debris but instead to collapsed flexible pipes. Flexible pipes can degrade over time and then start to collapse inwards, particularly at any bends, reducing and eventually completely stopping the water from flowing.

This was the case with my pool so I had to replace all of the pipework from the skimmers to the pump with rigid pipes. This was quite a bit of work as you can see from the picture below but it solved the problem.

3. Is the skimmer weir door functioning?

If plenty of water is being drawn into the skimmer, and you can see debris being pulled in through the hole, but it doesn’t stay there (particularly once the pool pump is off) then you probably have a problem with the weir door.

The weir door contains a floating medium that keeps the top of the door roughly level with the pool’s surface. The suction draws water (and any debris) over the top of the door and traps it inside the skimmer.

Check that the float medium is still there as normally it is just a push fit so they can become dislodged.

You could have a twig or some other debris stuck in the door somewhere that is preventing it from floating at the correct level or, as happens in my swimming pool from time to time, one of the small plastic “hinges” may have come out of one of the holes in the skimmer side so it is no longer swiveling.

Pool Care Handbook and Video Course

When I bought my house with a swimming pool, I knew absolutely nothing about pool care. I just winged it for a while, making many mistakes along the way.

Fortunately, I was recommended Swim University’s Pool Care Handbook and Video Course. I bought it and it was an absolute game-changer.

It was the best money I spent that year. I learned everything from basic cleaning to advanced troubleshooting. Swim University offers a no-quibble refund policy too so what do you have to lose?

Buy a floating robotic skimmer

If you have lots of debris in your pool, particularly if you have trees near your pool as I do so you are constantly removing leaves, which your skimmers struggle to deal with, then you may wish to look at adding a floating skimmer to help out.

These robotic pool skimmers are solar-powered and move around on the surface of the pool under their own power collecting debris as they go. You just need to take it out and empty it now and again (as you do a skimmer basket).

It saves you from having to use the skimmer net so often and because it moves around it can collect debris before it gets waterlogged and sinks to the bottom, particularly when the pool pump is off so the skimmers are not skimming.

There are two popular models available:

Ariel Solar Breeze Automatic Robot Pool Skimmer

The Aerial robotic pool skimmer works completely on solar power to remove surface debris as well as reduce the amount of dust, leaves, pollen and bacteria. It has a wireless app that you can use to control it.

The Aerial pool skimmer is available on Amazon

Betta SE (2023 Model) – Solar Powered Automatic Robotic Pool Skimmer

The Betta SE – Solar Powered Automatic Robotic Pool Skimmer removes surface debris as well as reduces the amount of dust, leaves, pollen and bacteria.

It has an intelligent onboard navigation system that maps the water surface and targets dirty areas. It has updated salt and chlorine tolerant motors and is 100% solar powered.

The Betta SE is available on Amazon