What To Know
- Overloading of the air compressor or electrical faults can cause the fuse to blow or the circuit breaker to trip.
- If the piston or compressor head becomes seized due to wear or lack of lubrication, it can prevent the compressor from starting.
- This could be due to worn or broken valves, leaking seals or gaskets, a clogged unloader valve, or a faulty pressure switch.
If you’re experiencing the frustrating issue of your air compressor humming but not starting, you’re not alone. This common problem can be caused by various factors, and diagnosing the exact cause can be a challenge. To help you get your air compressor up and running smoothly again, we’ve compiled a comprehensive troubleshooting guide that covers all the potential reasons why your air compressor may be humming but not starting.
Electrical Issues
1. Faulty Power Cord or Connections
A faulty power cord or loose connections can prevent power from reaching the air compressor, causing it to hum but not start. Inspect the power cord for any damage or loose wires. Ensure that the power outlet is securely connected and providing power.
2. Blown Fuse or Tripped Circuit Breaker
Overloading of the air compressor or electrical faults can cause the fuse to blow or the circuit breaker to trip. Check the fuse or circuit breaker panel and replace the blown fuse or reset the tripped circuit breaker.
3. Malfunctioning Pressure Switch
The pressure switch regulates the air pressure in the tank and controls the compressor’s operation. A faulty pressure switch can prevent the compressor from starting or cause it to hum continuously.
Mechanical Issues
4. Seized Piston or Compressor Head
If the piston or compressor head becomes seized due to wear or lack of lubrication, it can prevent the compressor from starting. Listen for any unusual noises or vibrations that may indicate a seized component.
5. Worn or Broken Valves
Valves play a crucial role in directing air flow through the compressor. Worn or broken valves can cause the compressor to hum but not build up pressure.
6. Leaking Seals or Gaskets
Leaking seals or gaskets can allow air to escape, causing the compressor to hum but not deliver sufficient pressure. Inspect all seals and gaskets for damage or wear.
Other Issues
7. Low Oil Level
Insufficient oil can cause the compressor to overheat and seize. Check the oil level regularly and add oil as needed according to the manufacturer’s instructions.
8. Dirty Air Filter
A dirty air filter can restrict airflow, causing the compressor to overheat and hum. Clean or replace the air filter regularly.
9. Clogged Unloader Valve
The unloader valve releases pressure when the compressor is turned off. A clogged unloader valve can prevent the compressor from starting or cause it to hum continuously.
Troubleshooting Steps
1. Check for electrical issues (power cord, connections, fuse, circuit breaker, pressure switch).
2. Listen for unusual noises or vibrations that may indicate a seized component.
3. Inspect valves for wear or breakage.
4. Check seals and gaskets for leaks.
5. Check oil level and add oil as needed.
6. Clean or replace the air filter.
7. Inspect and clean the unloader valve.
Wrap-Up
Diagnosing the exact cause of why your air compressor is humming but not starting can be a process of elimination. By following the troubleshooting steps outlined in this guide, you can identify the underlying issue and take the necessary steps to resolve it. Remember to always refer to the manufacturer’s instructions for specific maintenance and troubleshooting information.
Frequently Discussed Topics
Q: Why is my air compressor humming but not building pressure?
A: This could be due to worn or broken valves, leaking seals or gaskets, a clogged unloader valve, or a faulty pressure switch.
Q: What does it mean if my air compressor is humming and vibrating?
A: Humming and vibration can indicate a seized piston or compressor head, worn bearings, or loose components.
Q: How often should I change the oil in my air compressor?
A: Oil change intervals vary depending on the type and usage of the air compressor. Consult the manufacturer’s instructions for specific recommendations.
