Common reasons for the powder spraying gun not feeding powder
- Spray Gun and Powder Supply Not Cleaned Regularly
Accumulated powder around the nozzle or diffuser creates blockage inside the spray gun, restricting airflow and powder flow
- Contamination or Impurities in Powder Coatings
Foreign particles mixed in the powder can block the injector, venturi, or spray nozzle, resulting in zero powder output
- Moisture Absorption and Powder Clumping
Powder coatings absorb moisture easily. Once clumped, they lose fluidity and cannot be conveyed through the powder hose
- Insufficient Operating Air Pressure
When air pressure is too low, the spray gun cannot generate enough suction to transport powder.
- Solenoid Valve Not Working
A malfunctioning solenoid valve prevents the release of conveying air, causing the gun to stop delivering powder
- Blocked, Bent, or Incorrectly Connected Powder Hose
A twisted, bent, or loose hose interrupts powder flow. Even worse, connecting the “injector air” and “dilution air” lines incorrectly will stop powder output entirely
- Poor Contact in Control Cables or Trigger Switch
If pulling the trigger does not activate the main unit (no “click” sound), the electrical signal is not reaching the controller
- Dilution Air Pressure Too High
Excessive secondary air (dilution air) blows the powder away and disrupts the venturi effect, making the gun appear to have “no powder”
- Low Input Voltage (220V AC)
Low or unstable voltage can cause solenoid valves not to open fully—an often overlooked but increasingly common cause
- Clogged Injector or Powder Nozzle
Powder buildup inside the venturi injector prevents smooth powder flow
How to Solve the “No Powder Output” Problem?
- Clean the Spray Gun and Nozzle Regularly
Prevent powder buildup that restricts airflow or blocks the diffuser
- Sieve Powder Before Use
Remove clumps and contaminants to improve powder fluidity and prevent clogging
- Dry Moist Powder Properly
Use low-temperature drying equipment to restore powder flowability
- Increase Air Pressure and Adjust Gun Distance
Ensure the system has enough conveying pressure for stable powder output
- Check Solenoid Valve Plugs and Wiring
Confirm that the solenoid valve activates correctly
- Inspect All Powder Hoses and Air Lines
Look for bending, damage, loose connections, or reversed air lines
- Verify Control Cable and Trigger Signal
Ensure consistent signal transmission from the spray gun to the controller
- Turn Off Dilution Air Completely and Test Again
This helps confirm whether excessive secondary air is interfering
- Stabilize Power Supply or Install a Voltage Regulator
A constant power supply ensures the solenoid valves function properly
- Clean Injectors and Perform Routine Maintenance
Regular inspection and cleaning prevent most powder flow failures
Conclusion：
The “no powder output” issue in powder coating equipment may seem minor but can significantly reduce production efficiency. By systematically checking powder quality, air pressure, solenoid valves, hoses, electrical connections, and power supply, operators can identify the root cause and resume stable spraying quickly.
