Commercial air compressor not working? Our air compressor troubleshooting guide will help you get to the bottom of compressor problems. Learn how to check your air compressor for common air compressor faults and identify solutions to get your production lines back up and running.
If you're dealing with a broken air compressor, an air compressor losing pressure, or other air compressor problems, the Aire Experts at Fluid-Aire Dynamics can help. We can help with air compressor fault diagnosis, low pressure troubleshooting, and air compressor repair services.
Table of Contents
- 1. Compressor Oil Is Leaking or Does Not Last Long
- 2. Air Compressor Is Overheating
- 3. Air Compressor Is Too Loud
- 4. Air Compressor Keeps Blowing Fuses
- 5. Air Compressor Will Not Start
- 6. Air Compressor Fails to Stop
- 7. Excessive Power Consumption
- 8. Air Compressor Does Not Generate Enough Pressure
- 9. Excess Oil in Discharge Air
- 10. Air Compressor Intake Obstructed
- Need Help with Air Compressor Troubleshooting?
Aire Tip: Before working on your air compressor, be sure to fully disconnect it from its power source and follow proper lockout/tagout procedures. Follow all safety precautions in your user's guide and contact a professional if you do not have the appropriate expertise on staff.
1. Compressor Oil Is Leaking or Does Not Last Long
Proper lubrication is absolutely essential for an oil-flooded rotary screw compressor or reciprocating air compressor. If oil levels are too low or the oil sump runs dry, you will quickly be faced with a damaged air compressor. Running without oil will damage the air end and lead to costly repairs.
An oil leak may show up as an obvious pool underneath the compressor, or you may simply notice that oil doesn't last as long as it should. This is most commonly due to:
- Worn seals and gaskets
- Damaged oil lines or reservoirs
- Loose fittings or connectors
- Faulty oil filters
- Overfilling the oil sump
What you can do:
- Check all seals, gaskets, fittings, connectors and other elements of the oil system for signs of wear, cracks or damage and replace any worn or damaged parts.
- Change the oil and install a fresh oil filter.
- Follow all operator instructions for oil changes, and do not overfill the oil sump.
2. Air Compressor Is Overheating
Air compressor overheating can be caused by a number of issues, including:
- Inadequate lubrication
- Poor ventilation
- High ambient temperatures
- Clogged filters or hoses
- Problems with the air compressor cooling system
- Over-cycling (exceeding the recommended duty cycle)
What you can do:
- Make sure you are operating the compressor within its recommended duty cycle.
- Check the oil system to be sure it is cycling oil properly. Add oil if oil levels are low, and change the oil if it appears dirty or degraded.
- Check intake filters, inline filters, pipes and hoses. Remove any blockages and change filters if they are dirty or loaded.
- Be sure the compressor room is adequately ventilated and ambient temperatures aren't too hot. Add fans or cooling if necessary.
- Check the cooling system and aftercoolers to make sure they are clean and working properly. For air-cooled systems, ensure that the fans are working. For liquid-cooled systems, check water or coolant levels.
3. Air Compressor Is Too Loud
Excess noise in an air compressor is often an early indicator of a developing problem. While commercial air compressors can be pretty noisy naturally, if you notice a change in noise levels or new noises coming from the compressor, it's wise to check it out. Noise issues may be caused by:
- Loose, worn, damaged or misaligned parts (bolts, belts, pulleys, etc.).
- Improper mounting of the compressor, leading to excess movement or vibration.
- Poor lubrication (this may cause a squealing or screeching noise).
- Misalignment of screws (in a rotary screw air compressor) or problems with pistons (in a reciprocating compressor).
- Bad motor bearings.
What you can do:
- Check the motor bearings. Make sure they are properly lubricated, and replace them if they are worn or damaged. (You may be able to do this yourself in a piston or reciprocating air compressor; screw compressor bearings should only be replaced by a professional.)
- Check all bolts, belts and pulleys. Replace worn or damaged parts and tighten things down as necessary.
- Make sure the compressor is properly mounted, and tighten down any loose bolts. A rubber mat can absorb excess vibrations. (Check out more tips for reducing compressor noise.)
- Ensure that the air end has proper lubrication and the rotors or pistons are moving freely.
- If there appears to be a misalignment inside the air end causing the problem, it's best to call a professional to determine if it's time for an air end rebuild.
4. Air Compressor Keeps Blowing Fuses
Repeatedly blown fuses in your air compressor may indicate an underlying electrical problem. This could include a range of issues, such as an electrical short, a faulty motor, or an overdraw of electrical current due to the compressor working harder than it should. Some potential causes include:
- Overloaded circuits due to other high power-consuming devices sharing the same circuit with the air compressor.
- The motor of the air compressor is failing or is worn out, which causes it to draw more current than normal.
- Electrical wiring issues within the air compressor, including damaged wires or loose connections.
- The compressor is running too hot.
- Running the compressor over its rated PSI.
What you can do:
- Make sure the circuit where the compressor is plugged in isn't overloaded with other high power-consuming devices. Your air compressor should ideally be on its own dedicated circuit. Check to make sure the circuit is rated for your compressor's amperage.
- Inspect the motor for signs of wear or damage. Replacing a faulty motor can often resolve issues with blown fuses.
- Check motor amperage for signs of motor damage.
- Look for signs of damaged wires or loose connections and make necessary repairs.
- Ensure the compressor is operating in a cool, well-ventilated area.
- Regularly maintain your compressor and ensure that the compressor's cooling system is functioning properly.
- Do not run the compressor over its rated PSI.
5. Air Compressor Will Not Start
If you push the start button and nothing happens, you may think the air compressor is broken — but that is not always the case. There are several reasons an air compressor fails to start, and some of them are simple to fix.
If your compressor is humming but not starting, you know it at least has power. It is likely that the problem lies either in the motor or the air end. Common issues include:
- Failed capacitors
- Damaged motor windings
- Overload protection activation
- Check valve failure
- Blocked intake filters
- Air end bearings failure
If nothing happens at all, it could be:
- Power issue or blown fuse
- Faulty starter
- Cut-in pressure settings (cut-in pressure set too low)
- A mechanical and electrical failure inside the motor
- Bad start switch or control board
What you can do:
- Before anything else, check the power connections. Ensure that the power cord is properly connected and that the power switch is turned on. If necessary, check the circuit breakers as well.
- If the compressor still doesn't start, check the cut-in pressure settings. Try adjusting the cut-in pressure settings to see if the compressor will start.
- Make sure the check valve and starter are working properly and there are no blockages in intake filters.
- If after following these steps your air compressor still doesn't start, it might be best to call a professional for further diagnostics and repairs.
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6. Air Compressor Fails to Stop
An air compressor is designed to stop working once the tank pressure reaches the cut-off point. If your air compressor fails to stop, it may be due to the following reasons:
- A faulty pressure release valve
- A defective power switch
- Defective pressure switch
What you can do:
- If your air compressor doesn't stop once the tank pressure reaches the cut-off point, you should immediately cut the power to the compressor. Over-pressurizing the system can be very dangerous. Check the relief valve and replace it if it is faulty.
- If replacing the relief valve doesn't resolve the issue, the problem might be a defective pressure switch. The pressure switch sends a signal to the compressor's internal controls to stop working once the tank pressure reaches the cut-off point. Replacing the pressure switch should resolve the issue.
7. Excessive Power Consumption
Industrial air compressors are significant power consumers, but excessive power consumption can indicate underlying issues affecting efficiency and performance. Common causes include:
- Neglecting regular maintenance tasks like cleaning and lubricating parts, changing air and oil filters, and draining condensation
- Air leaks in the system
- Operating at higher pressures than needed
- An aging or failing air compressor motor
What you can do:
- Keep up with routine maintenance tasks such as changing the oil, cleaning or replacing air and oil filters, and checking for and repairing any leaks.
- Ensure the compressor is only operating at the pressure required for your operations. Adjusting the pressure to match your needs can significantly reduce power usage.
- If the compressor is outdated or the motor is inefficient, it might be more cost-effective in the long run to upgrade to a newer, more energy-efficient model, such as a Variable Speed Drive (VSD) air compressor.
- If power consumption remains high despite addressing these factors, consider bringing in a professional to perform an energy audit. They can identify areas of inefficiency and suggest ways to reduce energy usage.
8. Air Compressor Does Not Generate Enough Pressure
If you're having pressure problems, the first thing to determine is whether the issue lies with the compressor or the distribution lines. Attaching pressure gauges at the air compressor outlet and at the point of use can help with air compressor low pressure troubleshooting.
- If the air compressor is generating the correct PSI, but you're not getting enough pressure at the point of use, the problem lies in the distribution lines. Air leaks in distribution pipes, blocked inline filters, and leaky or too many quick-couplers and hoses are common culprits of pressure drop through the distribution system.
- If the compressor is not generating enough pressure, the problem could be in the air end (e.g., leaks between high-pressure and low-pressure pistons, misalignment of rotors on a screw compressor, leaky seals or gaskets, etc.). Or, it is possible that the intake is blocked or the discharge pressure valve is faulty on a screw compressor.
- Finally, it may be that the compressor is not sized correctly for the application. If you are using more air (CFM) than the compressor is rated for (at a particular PSI), the compressor will not be able to keep up.
- Note: If you throttle the discharge/service valve to the plant back slowly and you get full amperage on the compressor, the compressor is most likely not the issue. In this case, the compressor is too small or the distribution system is at fault.
What you can do:
- If the problem lies in the distribution system, first check inline filters and change them if they are loaded. Limit the use of quick couplers and hoses. Finally, have an air leak study performed. (Your power company may pay for this.)
- Make sure the pressure is set correctly and the pressure regulator is functioning. Replace the pressure regulator if necessary.
- Check intake valves and filters to ensure valves are working correctly and there are no blockages.
- If the problem lies in the air end, it's probably best to call a professional. It is possible that the air end will need to be rebuilt.
9. Excess Oil in Discharge Air
Excess oil in the discharge air can happen when the oil that is used for lubricating, cooling, and sealing the compressor ends up in the compressed air that is discharged from the unit. There are several possible causes for this issue, including:
- Malfunction in the oil separator, which is supposed to remove oil from the discharge air before it leaves a screw compressor.
- The oil level in the sump is too high due to overfilling or a malfunction in the system that controls the oil level.
- A blockage in the oil return line, which could prevent oil from being returned to the sump from the separator of a screw compressor.
- Oil viscosity issues, due to using the wrong oil or oil being too hot or too cold.
What you can do:
- Check oil levels and oil quality. Drain excess oil or change the oil and filter to start. If you see signs of sludge or varnish in the oil, contact us for a varnish remover to be run through the compressor. Be sure you are using the recommended oil for your compressor.
- Check the oil return line for blockages. Clean out any sludge, rust or debris in the oil line or replace it if necessary.
- Make sure the oil separator is functioning correctly. If the separator is faulty or worn out, it should be replaced; this is also increasing your energy costs.
- If you are still experiencing excessive oil carryover in your compressed air, consider upgrading your inline filtration to remove oil droplets from the air supply.
10. Air Compressor Intake Obstructed
The air intake of your compressor plays a crucial role in its operation. If the air intake gets clogged or blocked, it can lead to several issues, including reduced air pressure, overheating, and increased energy consumption. Here's what might cause it:
- Failing to replace the air intake regularly can lead to a build-up of dust and debris, causing it to become clogged. Loaded or damaged intake air filters will restrict the airflow.
- A faulty inlet valve on a screw compressor will prevent the compressor from being able to draw in air when needed.
What you can do:
- Replace the air intake filter regularly to prevent a build-up of dust and debris.
- Regularly check the air filters and replace them if they are clogged or damaged.
- If the inlet valve is faulty, it will need to be replaced or rebuilt.
Need Help with Air Compressor Troubleshooting?
Whether your air compressor is not working, is exhibiting unusual behavior, or simply isn't operating as efficiently as you would like, Fluid-Aire Dynamics can help. We are the experts in commercial air compressor troubleshooting, compressed air system audits and compressor repair. Contact us for air compressor preventative maintenance and inspection to keep your system operating in top condition. Have an immediate air compressor problem? We offer 24/7 emergency repair services with a four-hour response guarantee for customers within 90 miles of our service centers in Chicago, Milwaukee, Minneapolis, Detroit, San Antonio and Philadelphia.
Contact us for air compressor service and repair.