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.

Pool Skimmer No Suction: A pool skimmer with no suction can indicate a clogged or damaged skimmer basket, a blocked skimmer line, or a faulty pump. To fix the issue, clean or replace the skimmer basket, remove any debris blocking the skimmer line, and check the pump for any malfunctions.

Possible reasons why your pool skimmer not working

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 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, 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, check that water starts coming in when you push the float down.

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, 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 the 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 too much water is 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 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 reduce 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, it may be clogged and need cleaning.

Stuck pool float valve assembly

You may have a pool float valve assembly in some skimmers (with two holes at the bottom). 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 is 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 air trapped in the pool filter housing 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 okay, 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 to 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 (i.e. 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.

Possible collapsed flexible skimmer pipes

If all else fails, you may have a blockage in the skimmer line 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.