Air Compressor Wont Shut Off (Tips & Troubleshooting)

One of the most common problems people encounter with their air compressor is the machine not shutting off properly. An air compressor that does not shut off after reaching the cut-off pressure will be at risk of incurring damage due to an exceeded duty cycle.

The most common causes of an air compressor that won’t shut off properly are an air leak, a faulty pressure switch, dirty filters, and broken air gauges. If you are experiencing any of these issues, it is likely that your air compressor will not shut off properly.

This guide will cover these issues in detail so that you can better understand the cause of your air compressor issues and resolve them quickly and easily. It is important that you accurately identify and resolve the issues causing your air compressor to not shut off.

If you do not address the issue, you could risk incurring up to 30 percent more energy costs with decreased efficiency as well as damage to your machine.

Common Causes Of An Air Compressor Not Shutting Off

The most common causes of an air compressor not shutting off are air leaks, faulty components, and dirty filters. All of these common causes will be discussed in detail in the list below. You should use this information to accurately diagnose your issue so that you can resolve it accordingly.

Air Leak

An air leak will cause your air compressor to not shut off properly due to the loss of pressure caused by the leak. Your air compressor depends on the pressure build-up to trigger the cut-off pressure settings put in place on the machine by the manufacturer.

If your air compressor never reaches the proper pressure level to trigger the shut-off, then you could risk wasting up to 20 or 30 percent more energy due to an exceeded duty cycle. There is also an inherent risk of damaging your machine if it does not receive the proper downtime triggered by the cut-off pressure.

You should inspect all of the hoses, tubes, and connectors for your air compressor if you suspect that you have an air leak. If your tank has a leak, you will need to replace it or weld the leak shut using a high-powered torch.

If you need to replace your air compressor tank, you can do so for an average cost of around $125 to $325, depending on the size of the tank. Your air compressor components such as the hoses, tubes, and connectors can be found for varying prices depending on the vendor.

You should use the table below to help you find the best deal when searching for air compressor components.

Faulty Pressure Switch

A faulty pressure switch is another common cause of an air compressor not shut off properly. The pressure switch is responsible for many of the main internal controls of an air compressor. The pressure switch is meant to respond to the cut-off pressure settings that you have set up on your machine.

If the pressure switch is faulty, this will cause your air compressor to not be shut off properly when the cut-off pressure is reached. You can easily replace the pressure switch on your compressor yourself with the right mechanical knowledge.

You can purchase a new pressure switch for your air compressor for around $65. The table below contains cost information regarding pressure switches from a few of the most popular online vendors.

Dirty Filters

Dirty filters are one of the most common causes of an air compressor not shutting off properly. If your air compressor’s filtration system is clogged due to dirty filters, this could affect the airflow pressure and cause your machine to not shut down correctly.

You should inspect all of your air compressor filters and replace any that are clogged and dirty. You can find replacement air compressor filters for an average cost of $15. You can save money buying your air compressor filters online. The table below contains several popular vendors and their prices for filters.

Broken Air Gauge

A broken air gauge can also cause your air compressor to not shut off correctly. Air gauges help to mitigate and detect the level of pressure build-up within your air compressor. Without properly functioning air gauges, your machine will have trouble reaching or detecting the proper shut-off pressure, causing your air compressor to not shut off properly.

You can identify a broken air gauge by turning off the compressor and listening for any escaping air coming from the gauges. If you hear a light hissing noise coming from the gauges, this is a strong indication that you need to replace them.

You replace the air gauge yourself for relatively cheap. You can expect to pay around $12 for a new air gauge for your compressor. Use the table below to find the best price for a replacement air gauge for your air compressor.

Troubleshooting Husky Air Compressor

Husky air compressors operate with oil-free motors and usually cut out at around 175 PSI.

If your Husky air compressor won’t shut off, likely the pressure switch is to blame. Like in the Bostitch models, if the pressure switch is faulty, your air compressor will automatically shut off when it’s supposed to. It is typically triggered when the maximum PSI is reached.

We talked about adjusting the pressure switch settings above; let’s now discuss replacing the part.

Troubleshooting

1. Unplug and turn off everything– For any troubleshooting, make sure to cut off any power source to the air compressor that might result in electrocution.
2. Depressurize the air tank– Remove all of the air from the metal drain. Once the hissing stops, the tank is empty.
3. Remove the cover– This will require a screwdriver.
4. Take off the manifold– Use the same screwdriver to undo its screws.
5. Remove the wiring– Undo the wiring from the old pressure switch (beware these can be hot- wear gloves), and take off the pressure gauge for manipulation purposes.

Install the new pressure switch– This requires some re-wiring. Take a look at this short video to help with the visual process.

Troubleshooting Dewalt Air Compressor

The Dewalt air compressor has a cut-out setting of 200 PSI- much higher than the models mentioned above.

The most common issue that won’t allow a Dewalt air compressor to shut off is a malfunctioning gauge on the air tank. This results in a pressure misreading and may not signal the machine to kick off at 200 PSI. Often, it is a result of corrosion.

This can be incredibly dangerous if your air tank is overpressurized. The good news is you can easily replace the gauge.

1. Unplug and turn off everything– For any troubleshooting, make sure to cut off any power source to the air compressor that might result in electrocution.
2. Depressurize the air tank– Remove all of the air from the tank by pressing the metal piece button attached to the yellow tubing. Once the hissing stops, the tank is empty.
3. Remove the cover– This will require a screwdriver (a ratcheting version works best).
4. Take off the manifold– Use the same ratcheting screwdriver to undo its screws.
5. Remove the air tank gauge– This is located in the very middle and requires a wrench for the first few turns.
6. Install the new air tank gauge– Screw the new piece into place, finishing with a wrench.
7. Reassemble your air compressor– Put everything back together, plug it back in, and it’s fixed!

Troubleshooting Craftsman Air Compressor

A Craftsman air compressor cuts out at about 175 PSI, depending on the particular model you chose. They come with large, 33-gallon tanks and oil-free motors.

The most prevalent cause of a Craftsman air compressor not shutting off is pressure relief valve (also known as a safety valve) damage. This part could be threading improperly, causing excess air to be released from the tank, or the spring inside could be worn.

A pressure relief valve is used for sensing the pressure in an air compressor. It’s intended as a last resort to shut off the compressor when the preset pressure limit has been reached (in this case, 175 PSI).

It’s essential that your pressure relief valve is working properly, so there is no over-pressurization of the air tank. If this valve is being triggered, it’s possible that the pressure switch is not being signaled to do its job.

There are a couple of ways to address this problem.

1. Unplug and turn off everything– For any troubleshooting, make sure to cut off any power source to the air compressor that might result in electrocution.
2. Depressurize the air tank– Remove all of the air from the tank by unscrewing the drain underneath the machine (look at the manual for its exact location). Once the hissing stops, the tank is empty.
3. Remove the manifold cover– This will require a small screwdriver.
4. Unscrew the pressure relief valve– This part will require a wrench for the first few turns.
5. Check out the threads– If the threads look intact, it may just be that the knob was screwed on incorrectly. If that’s the case, re-screw it properly. Otherwise, if the threads look damaged, you may need an entirely new pressure relief valve.
6. Look for spring damage– If the spring on your valve becomes stuck open, then it’s time to replace it for around $6.
7. Make sure to purchase the correct piece– The Craftsman air compressor pressure relief valve is preset to release at 175 PSI. You need the correct one for your model.
8. Install the new pressure relief valve– Screw in the new piece to the manifold first by hand, then tighten with a wrench. Make sure to follow the threads.
9. Reassemble your air compressor– Put everything back together, plug it back in, and you should be good to go!

Is It Dangerous If My Air Compressor Will Not Shut Off?

Yes. If your air compressor won’t shut off, you are on the edge of disaster. While there are several mechanisms in place to prevent a high-pressure tank rupture, if your air compressor will not turn off, you are depending on one or two small devices to prevent an explosion.

At What Pressure Should An Air Compressor Shut Off?

That depends on what you set it at, but the general rule is that the difference in pressure must be at least 14.7 PSI or 1 BAR. If you set the pressure level any lower than this, it will cause the compressor motor to turn off and on again rapidly, which is not good for the motor. 

Final Thoughts

This guide has provided you with all of the information that you need to accurately identify and resolve the issue causing your air compressor to not shut off properly. You should address any issues that you have with your air compressor not shutting off as soon as possible.

An air compressor that doesn’t shut off will incur up to 30 percent more energy costs and could also risk damaging the internals of your machine. Because of this, it is important to use the information provided in this guide to help you resolve your air compressor issues.

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