Shop-Vac Blowing Water Out – 3 Solutions For This Problem

You have always wanted an easy way to clean up the mess in your home or workplace. And now after finally get one, you realize that the Shop-Vac is starting to blow the water out anytime you attempt to use it.

Unlike the regular vacuum cleaners, the Shop-Vac has multiple functions, capable of sucking up both dry debris and liquid substances. The utility goes beyond tidying up carpets of tiles; it is also for sucking objects out of drain pipes or cleaning up puddles in leaky basements.

But the issue with these tools is that as reliable as they might seem at first, they will break down when overused, wrongly operated or not properly maintained. For instance, in your case, sucking up large amounts of liquid can break the Shop-Vac.

Why is your Shop-Vac Blowing Out water?

Well, to all problems there is a solution, but before we move further, you should take a quick look at your tool to see that the things are connected rightly, especially the hose.

Ensure the hose is on the port that says Vacuum not Blow. If this is right, then you see other reasons – so lets quickly run through the causes and three solutions to a Shop-Vac blowing water out.

Is your Filter clogged?

Sucking up several substances with the filter in Shop-Vac will at one point need some maintenance. When it is not properly maintained, it will clog and blow out the water instead of sucking it in. In this case, the type of filter matters, and if your Shop-Vac uses a reusable filter – uninstall it, wash, and try again.

The clogged strainer can only be a problem if it is the right one for the task because the filter for vacuuming dry debris is different from the one for wet pickups. Using the wrong one can make the Shop-Vac blow out water instead of vacuuming it.

Also, some professional users have recommended, you may leave the filter in place while picking up small amounts of liquid, but it must be dried afterward to avoid possible mildew or damage. When picking up large quantities of water uninstalling it is preferable to prevent mist appearing on the exhaust due to saturation.

But if you must, install a new filter and try sucking up clean water to be sure that the motor is not acting like a fan or a pump and blowing water through the tank. Just in case, it is a wise decision to take it outside to avoid risking water spraying all over.

Here’s also a video on how to clean the filter:

The Tank level also matters

Now if you have tried to vacuum without the filter installed or even used a new filter and you are experiencing the same problem of water blowing out, you should check the tank. Ensure the container is not too filled to receive more water and reacting by returning it.

It happens in some models that when the container is over half filled, the water that is picked up foams in the vacuum head and comes out through the exhaust port. Well, this will hardly happen without the filter in place, but it is possible!

There is a floating device to prevent liquid from reaching a set height to prevent it from interfering or damaging the motor and its electrics. A little concern is that not all Shop-Vacs are equipped with a float or a similar device to prevent liquid from getting sucked into the motor and exhaust from the container.

From the inlet point of the hose, you should check the tank for an elbow pointing downward. If it is clear of water, then the suction motor will pick up water without returning it. Also, some misting is normal during vacuuming, but there should not be lots of water.

Still, on the tank, turn the top of the vacuum around to be in the opposite direction from the suction hose. Check the float ball cage to confirm that it is working. If the bucket is filled, empty it immediately you notice water expelling out of the exhaust to prevent damages.

Check the Hose Connection

Maybe not blow out so much, but a loose connection will cause water expelling from the Shop-Vac. A loose hose will have less to do with maintenance, but a lot with the operation.

When connecting the hose to the Shop-Vac ensure that it is tightened enough, some use hose locks, which is better. When it is connected rightly, you still need to check that there is no hole in it.

A loose hose or holes in the hose will do more than blow the water out; it will also reduce suction from the dry pickup, which is why damaged it should be replaced.

How does the Shop-Vac work?

The Shop-Vac does not work like a pump that forces out the liquid the way it takes it in. Instead, it evacuated the air from the container, blowing it out through the exhaust port. While this happens, the air pressure in the tank reduces, allowing it to pick up debris, dust, or even liquid.

Big shop vacuum cleaner

It is a simple counter-action of normal air pressure leaving the vacuum and accepting other substances through the hose. Thanks to gravity, the debris or liquid in the air flow will drop to the bottom of the container.

While these substances come in some particles will get caught in the air stream and try to evacuate the Shop-Vac with the air. This is where the filter comes in – it strains only particles over a certain size out of the evacuated air stream.


Originally, even if there might be some liquid in the outlet air, the Shop-Vac is not designed to act as a spray system. The liquid is only as a result of the water in the tank, reaching a certain level where the air begins to skim from the surface of the liquid in the container.

Bear in mind that without the filter, a lot of mess can occur. Its purpose is to clean the air that is being evacuated and also protect the motor and fan. Also, in this process, when the wrong filter is being used, it could quickly clog or even disintegrate and be pulled through the fan.

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