5 Reasons Your Air Compressor Has Water In It

Air compressors are necessary for countless businesses and hobbyists throughout the world. They are relatively easy to use and maintain, but it can be annoying when there’s more water build-up than usual. So, why is water coming out of an air compressor hose?

Water coming out of an air compressor hose typically means that dew forms because of the difference in air temperature inside and outside the compressor. This can also happen if you push the pressure or flow rate too far which causes extra moisture to accumulate. Otherwise, you’ll find more water in the hose if there is debris in the line or if you work with corroded air tools.

It isn’t the end of the world when you find water in your air compressor, but it can be annoying. Follow along as we explore why your air compressor hose has water in it and see what you can do to fix it.

Why Is My Air Compressor Spitting Out Water?

Whether it be a high flow rate or blockages, there are several reasons for water coming out of an air compressor hose. Let’s look at the 5 most common reasons your air compressor has water in it.

1. Water Separates From Air

Compressors pull air into the machine to compress it and push it back out. The air that enters a compressor contains moisture, and the moisture level typically decreases within the machine. That’s because the temperature of the air inside the compressor is different from the outside air.

The air and water cool down inside of an air compressor, and that can cause dew to form within it. You will find dew within the condensate tank, but you will also find it within the hose. Water coming out of a compressor hose isn’t always a bad thing, but it can be bad if there’s too much.

Most seasoned air compressor operators drain the condensate tank each day, but it’s easy to overlook the hose. Check the hose daily for water, especially if you keep your compressor in a particularly cold or warm environment. Water coming out of an air compressor hose is especially common during summer when cold and warm air mix more frequently.

2. Too Much Pressure

Of course, pressure is an essential part of an air compressor. That said, water coming out of an air compressor hose is a sign that there’s too much pressure. Each air compressor has a different ideal pressure level, and exceeding it can produce more condensation than normal.

Use the correct PSI level for the tool you connect your air compressor to. For example, you shouldn’t run your compressor at 100 PSI for an air tool that’s rated for 75 PSI. The extra pressure will increase the condensation level, and water will get trapped in the hose. Check the components within your compressor instead of increasing the pressure if you can’t reach the ideal level.

There’s a good chance there’s a blockage or build-up of water or oil instead of a problem with the pressure itself. The surrounding temperature can also make pressure accumulate within your air compressor. More pressure will build up if your compressor is in a hot environment.

3. High Flow Rate

The flow rate of an air compressor is measured as CFM or cubic feet per minute. This refers to how much air can flow throughout the compressor depending on the pressure within the unit. For example, small air compressors meant to fill up tires need a flow rate of just 10 CFM.

Industrial air compressors typically have a flow rate of 200 CFM because more airflow is needed. You can significantly increase the moisture within your compressor’s hose if you push the flow rate beyond the necessary level. Not only will water come out of the hose, but you can also damage the air tools you use.  

A high flow rate is a bigger problem if you have a small air compressor and hose. There is less space for the condensation to be stored in the tank, so more of it will wind up in the hose. Stick to the flow rate that your compressor and air tools are rated for to avoid this problem.

4. Blockages in the Hose

Pressure can also build up and your compressor can spit out water due to blockages in the compressor and hose. Check the hose for debris and kinks if water is coming out of it. Plenty of particles and debris can get into an air compressor, especially in an industrial setting, garage, or workshop.

The easiest way to remove debris from an air compressor hose is to open the shut-off valve. Remove any air tool that is attached so the debris and water can easily escape. Turn up the pressure to the highest level your air compressor can handle.

Place a bucket beneath the line so you don’t make a huge mess in your workspace. Run the compressor until all of the water and debris are gone. Repeat this process as many times as you need for each of your lines. You will quickly notice that less water coming from your air compressor hose, and your air tools will perform better.

5. Damaged Air Tools

Air tools can diversify any compressor and make it more useful for many applications. That said, they require just as much maintenance as an air compressor and hose. They often feature narrow nozzles that can become clogged and corroded.

That is especially true if the tools feature metal components. Corrosion is the biggest threat to any air compressor, so you must check the metal parts daily for signs of it. Replace the air tool if it is so corroded that air can barely escape.

Clogged and corroded air tool attachments cause extra pressure and moisture to accumulate in the compressor. That’s because the air and moisture have nowhere to go, so the water will sit in the hose and condensate tank.

Should You Drain an Air Compressor After Every Use?

You should drain an air compressor after every use in most cases. That is especially true in an industrial or professional environment when you typically use the compressor more often. It ultimately depends on the size of your condensate tank and how quickly it fills up.

Ideally, you should never let the condensate tank fill with water completely. This can increase the chances of corrosion, and more water will end up in the hose. Instead, you should drain the tank when it is 50% full in most cases.

For example, you should drain the condensate tank when it is full of 30 gallons or less if you have a 60-gallon tank. This will make it easier to drain and will protect the lines and metal components from excessive moisture exposure.

So, Why is Water Coming Out of an Air Compressor Hose?

Water comes out of an air compressor hose because moisture builds up when water separates from air. Air compressors cool outside air when it enters the unit, and this causes condensation to accumulate in the line and tank. Keep your air compressor in a moderate environment as excessive heat and cool air make the condensation worse.

Check the hose for debris and kinks each day, and replace damaged or corroded air tools. Blocked nozzles cause excessive pressure and more water will wind up in the hose. Avoid blasting the flow rate or PSI beyond what your system or air tools can handle, or water will leak out of the hose and quickly fill the tank.