The most common problem that every air compressor user faces of any brand is their tool is not turning off even after reaching the maximum cutoff pressure. We were also facing this issue on one of our compressors and fixed it quickly. There are some reasons why this happens, and you must follow a few steps to resolve the compressor not shutting off issue. We’ve provided below the causes why your device isn’t stopping and given the solutions to fix them.
10 Possible Causes of Why You Air Compressor is not Shutting Off
Here we have listed the problems and their solutions.
#1: It will be Air Leakage
You’ve turned on the air compressor to fill the required pressure; when it reaches maximum cutout pressure, you will notice it’s not turning off and continue running. There will be an issue of air leakage; check all the fittings on your compressor, there must be one of them leaking. To properly check the leakage, you can drop some water on all compressor’s fittings.
If you see any disturbance in the water flow, understand that part is leaking. The solution is simple: properly tight all the fittings, and if it is broken, replace it. After fixing, turn on the compressor; it will automatically turn off when it reaches the maximum pressure.
#2: Bad Pressure Switch
A pressure switch in an air compressor calculates the amount of pressure inside the tank and shuts off the system when it reaches maximum cutout pressure. It helps the compressor from blowing up by maintaining the internal pressure.
When the pressure switch becomes faulty, it will not turn off the compressor when the tank gets filled with maximum pressure. So, this is why your compressor is not turning off.
To solve this issue, you must replace the pressure switch that is available in online stores. If you don’t know how to change the pressure switch properly, follow the simple steps below.
- First, turn off the air compressor and remove the electric power connection.
- Keep in mind to release all the pressure by pulling the safety valve ring.
- If your compressor has a pressure gauge attached, then first remove it.
- Now, disconnect all the fittings attached to the pressure switch and carefully detach the pressure regulator.
- Uncover the pressure switch by removing all the screws and disconnecting all the available wires.
- Remove the safety valve carefully from the pressure switch
- Finally, kick out the old bad pressure switch that is attached to the tank.
- Now put the new pressure on the tank and reattach all the parts step by step.
After replacing the pressure switch, turn on your compressor, and we are 100% sure it will shut off when the compressor fills maximum pressure.
#3: Faulty Pressure Gauge
One of the common reasons that prevent the compressor from shutting off is its bad pressure gauge. The pressure gauge measures how much pressure is available in the tank. When it is not working correctly, the compressor continues to build the pressure, but due to a bad gauge, it fails to measure the tank pressure. That’s why the compressor fails to fill the maximum cutout pressure and won’t shut off.
Fixing this issue is very simple, get a new pressure gauge and replace it. If you don’t know how to install a new gauge, follow the steps.
- Switch off your compressor and drain the tank properly before proceeding.
- The pressure gauge is probably available on the top near the pressure switch.
- Unscrew it with the help of a wrench.
- Apply thread sealing tape to the new pressure gauge and fit it properly. That’s it!
#4: Leaking Gasket
Check the gaskets sitting on the valve plate in your air compressor; maybe they got bad. As the gasket helps to build pressure, it starts leaking air when it is worn out, and we don’t get the desired pressure. The compressor continues to provide its job to reach the cutout pressure, but due to a bad gasket, it won’t be able to build the required pressure. When the pressure doesn’t reach a maximum level, it will not turn off.
To solve this issue, you have to replace the gasket with a new gasket. The compressor will build the pressure on time and shut off when it reaches cutoff pressure.
#5: Drain Valve Left Opened
Sometimes it happens when you turn on the compressor; after a while, you notice that the tool isn’t shut off and not building the pressure. The situation is easy to understand; when the drain valve is left open, the compressor continues sending compressed air to the tank. Here tank’s drain valve isn’t closed, so all the pressure goes out from the valve. Now close that valve and rerun the compressor; it will start creating pressure as usual and stop on cutout pressure.
Keep in mind to check the drain valve once before switching on the compressor.
#6: Defective Pressure Relief Valve (PRV)
There is an automated system installed in every compressor that saves the tank from overpressure. Simply, there is a valve with a ring available on the compressor that releases the air when the tool builds more pressure than the maximum cutout; it is called a pressure relief valve. When the PRV gets bad, the compressor will not be able to release the excessive pressure from the tank inside.
The pressure continues to build, and that’s why the air tool doesn’t stop even on the maximum pressure limit exceeds. To fix this problem, you must replace that safety valve and install a new one. After installing the new pressure relief valve, the compressor will shut down when maximum pressure is filled.
#7: Dusty Air Filter
An air filter is a vital part of a compressor that functions to clean the air and remove excess dirt so the device can work smoothly. With time, the filter gets so much dirt that makes it difficult for the compressor to build the pressure. A compressor with a dirty filter rarely reaches the cutout pressure, and some guys think it is not shutting off. That’s right!
It will not allow you to build the pressure and keeps the machine running, so cleaning the intake filter is very important. Or, you can install the new filters to get the normal compressor working.
#8: Piston is dying
This is a very rare issue, it will happen with those people who own old air compressors. Old compressors with no proper maintenance face many problems, and the bad piston is one of them. The piston is located in the air pump where the air is compressed; when the piston is worn out or has broken rings, the pressure will not build properly. The compressor continues providing the job and very hardly fills the maximum pressure. Due to this issue, we think the compressor is not stopping.
To fix a bad piston, you have to replace the piston or its rings. When the new piston is installed, it again creates pressure and stops at the maximum level.
#9: Broken Check Valve
A check valve connects the air pump and the tank. It gets the air from the pump, sends it to the tank, and prevents reverse back. If the check valve gets bad, the incoming air from the pump will leak and don’t fill the tank. The compressor keeps providing the job even for long hours, but still, we will not reach the cutout pressure. That’s why the tool won’t shut off; you can quickly fix it. Take a new check valve and replace it carefully. Don’t forget to apply thread seal tape to avoid any leakage. Your issue will be fixed.
#10: Loose Belt
Many folks own a belt-driven air compressor, and their tool is not shutting off after turning on. A loose belt would be the reason because when the belt is loose, the wheel pulley will not be able to rotate the air pump properly. The belt continues to slip from the edges, and we don’t get the cutout pressure, and the compressor also keeps up its job. You have to replace the belt; see your tool’s owner manual to know the size of the belt. Once you install a new belt, it will build the air and shut off automatically when it reaches the maximum rating.
These are the problems that every compressor owner can face when his tool is not shutting off. We have also provided a DIY guide to fix those listed problems. You don’t need to pay any technician to resolve this issue; take that specific part from the market and do everything yourself. You can seek our help if your device faces any issues.
How to properly turn off the air compressor?
Switching off your compressor in a proper way is very important for the health of your tool. There is a pressure valve on every compressor; first, you must close it by pushing it down. Never forget to close the pressure switch before turning off the power switch. This way, your air tool’s pressure won’t lose. Now, turn off the power button.
Is it better to turn off the air compressor when not in use?
There is no issue if you keep your compressor ON, but when it is not in use, you can turn it off, which will help increase its life. Less pressure inside the compressor tank when you are not getting any job will provide longer life.