30 Common Problems and Solutions for Screw Air Compressors

To help users quickly troubleshoot common operational issues with screw air compressors and minimize downtime costs, we have compiled 30 frequently asked questions covering all aspects of equipment operation, maintenance, and fault diagnostics. The questions are presented in plain language, with straightforward, easy-to-follow solutions tailored for everyday factory maintenance and operations.

I. Startup and Power-Related Issues (Items 1–5)

Q1: The air compressor fails to start, and the display screen shows no output.

Solution: Verify that the external main power supply and the equipment’s circuit breaker are closed, and check for loose power cords or phase loss. Confirm that the emergency stop button has been reset and that the enclosure doors are fully closed. Inspect the control‑power fuses and relays for burnout or damage; replace any faulty components to restore normal operation.

Q2: When the start button is pressed, the device does not respond or operate.

Solution: Disconnect power and check whether the thermal overload relay has tripped; if so, reset it manually. Verify that the PLC controller parameters and the start‑signal wiring are intact and not open‑circuited. Inspect the motor terminal connections to eliminate loose or oxidized contacts; in severe cases, overhaul the motor windings.

Q3: The circuit breaker trips immediately upon starting the air compressor.

Solution: Prioritize troubleshooting motor short circuits and ground faults, and clean accumulated dust and oil from the wiring; verify that the supply voltage is not too low and that the three-phase voltages are balanced; inspect for head‑jamming and bearing seizure issues, and never attempt to start the equipment under fault conditions. After repairing any mechanically stuck components, restart the system.

Q4: The equipment frequently starts and stops, making stable operation impossible.

Solution: Verify the setpoints for the pressure upper and lower limits; an excessively small pressure differential can cause frequent cycling. Adjust the loading and unloading pressure differential appropriately. Inspect the piping for air leaks and check for signal drift in the pressure sensors; calibrate the sensors or replace any faulty components. Ensure stable gas supply to the workshop.

Q5: The machine cannot be restarted within a short period after shutdown.

Solution: The equipment is equipped with a delayed‑start protection feature; simply wait 3–5 minutes for the delay to expire. If the unit still fails to start after this period, check whether the temperature control or overload protection has tripped, reset the device’s protective circuitry, and verify that excessive ambient temperature is not triggering the start‑up protection.

II. Pressure and Air Supply Issues (Items 6–12)

Q6: The air compressor cannot build up pressure and fails to reach the set pressure.

Solution: Check whether the air intake filter is clogged; clean or replace the filter element. Inspect for insufficient opening or sticking of the intake valve, and clean the valve spool and cylinder. Verify that the piping, air receiver tank, and fittings are leak‑free, and seal any leaks. Confirm the equipment’s load to ensure it is not operated beyond its rated capacity.

Q7: The equipment operates normally under no-load conditions, but the pressure drops rapidly when load is applied.

Solution: Conduct a thorough inspection to identify large‑area leaks in the downstream piping and aging, leaking internal seals; check for malfunctions in the pressure‑maintaining valve and abnormal opening pressures, and repair or replace the valve as needed; inspect the oil‑gas separator for blockages, replace the separator element, and restore gas supply efficiency.

Q8: The air compressor cannot unload and continues to run at full load.

Solution: Inspect the pressure sensor for malfunctions or signal distortion, and calibrate or replace the sensor; check the unloading solenoid valve for sticking or wiring faults, and clean the valve spool; verify the PLC control program for errors, restart the controller to restore parameters, and reprogram and recalibrate if necessary.

Q9: The air compressor cannot load and keeps running at no-load.

Solution: Inspect the load solenoid valve for damage or blockage, and clean any debris from the valve body; check the intake valve actuator cylinder for air leaks and the diaphragm for damage, replacing any defective seals; verify that the control air line is free of obstructions or kinks, clear any blockages, and restore the intake‑load function.

Q10: The exhaust pressure fluctuates significantly, resulting in unstable air supply.

Solution: Investigate instances of sudden spikes in workshop gas demand and simultaneous operation of multiple gas‑using devices, and allocate gas supply accordingly; verify the accuracy of pressure switches and sensors, and calibrate pressure settings; clean impurities from the piping system, replace aged pressure‑regulating components, and stabilize the gas supply pressure.

Q11: After shutdown, the system pressure rapidly leaks and drops to zero.

Solution: Inspect the intake valve check valve and the one-way valve for inadequate sealing; clean carbon deposits from the valve spool, and replace it if wear is severe. Check the air tank drain valve and pipeline joints for air leaks, and tighten or replace the sealing components. Inspect the oil–gas separator pressure relief valve for malfunctions, and repair or replace the relief assembly.

Q12: Insufficient displacement fails to meet production requirements.

Solution: Regularly replace clogged air filters and oil–gas separation elements; clean the cooler and remove dust and oil buildup from the piping to reduce airflow resistance; inspect the compressor’s screw rotors for wear and excessive clearances—severe wear necessitates a major overhaul of the compressor; and optimize the workshop’s piping layout to minimize air‑supply losses.

III. Temperature and High-Temperature Faults (Items 13–18)

Q13: Air compressor high-temperature alarm and automatic shutdown

Solution: First, check the lubricant level; if it is too low, promptly top up with the same type of dedicated lubricant. Clean accumulated dust and oil from the air‑cooled radiator, and for water‑cooled models, verify the cooling‑water flow rate and temperature. Inspect for blockages or malfunctions in the thermostatic valve that prevent heat exchange, and replace any faulty thermostatic‑valve components.

Q14: The equipment operating temperature is too low, remaining below 75°C for an extended period.

Solution: Reduce excessive cooling water supply and adjust the cooling‑water flow rate; avoid prolonged no‑load operation of the equipment and appropriately increase the load; calibrate the temperature sensor to correct data deviations; inspect and maintain the thermal control valve to prevent prolonged full‑open conditions that can cause excessively low temperatures.

Q15: Frequent high-temperature tripping in summer, normal operation in winter.

Solution: Improve ventilation and heat dissipation in the equipment room by installing additional exhaust fans to prevent overheating in enclosed spaces; shorten the replacement intervals for filter cartridges and lubricants to ensure adequate cooling and lubrication; clear debris blocking the radiators, inspect the fan speed and check for any jams or obstructions, and repair any faulty fans.

Q16: Temperature sensor error; temperature display is abnormal.

Solution: Power off the system and inspect the sensor wiring for looseness or oxidation; retighten the terminal connections. Clean any dust or oil buildup from the sensor probe and recalibrate the temperature readings. If the sensor is aged or damaged, replace it to eliminate false alarms.

Q17: Excessive temperature, unusual noises, and overheating in the host unit’s head.

Solution: Inspect for lubricant degradation and carbon buildup, and replace with fresh lubricant as needed; check the compressor head bearings for wear and the screw rotors for binding—perform maintenance and lubrication for minor wear, and overhaul the unit if wear is severe; adjust the equipment’s operating load to prevent prolonged operation under excessive load.

Q18: The cooling fan is not spinning, resulting in ineffective heat dissipation.

Solution: Inspect the fan motor’s power supply and wiring for faults, and repair any wiring issues; clear debris that may be causing the fan blades to jam, and tighten any loose blades; if the fan motor is burnt out or the bearings are damaged, replace them directly to ensure proper heat dissipation.

IV. Lubricants and Oil-Containing Issues (Clauses 19–24)

Q19: The air compressor has high oil consumption and requires frequent oil top-ups.

Solution: Check that the oil level is not too high; if it exceeds the upper limit, promptly drain oil to bring it within the specified range. Clean the return oil line and the return‑oil check valve to clear any blockages. Inspect the oil‑gas separator element for damage or failure, and replace it immediately if the pressure differential exceeds the allowable limit. Avoid using non‑standard, low‑quality lubricants.

Q20: High oil content in compressed air and oil carryover at the point of use.

Solution: Replace the aged and failed oil–gas separator element, regularly monitor the filter differential pressure, clean the oil return line and check valve to ensure smooth oil return, adjust the pressure‑maintaining valve’s set pressure to prevent excessively low pressure that could result in incomplete oil–water–oil separation, and replace degraded, foaming lubricant.

Q21: Lubricant emulsification, whitening, and cloudiness

Solution: Investigate and address the issues of high humidity and excessive moisture in the equipment room to improve the indoor environment; inspect the cooler for leaks and verify that no water vapor has entered the oil circuit, then repair any leaking points; promptly replace the emulsified lubricant and flush the oil system to prevent corrosion of equipment components.

Q22: Lubricating oil forms carbon deposits and darkens, deteriorating rapidly.

Solution: Replace the lubricating oil strictly according to the equipment’s service interval to prevent over‑time use; avoid prolonged operation at high temperatures and promptly troubleshoot any cooling‑system malfunctions; use only the manufacturer‑approved, dedicated screw‑type air compressor oil, and never mix different grades; and regularly clean the oil‑line filters.

Q23: Excessive oil circuit pressure, oil circuit alarm

Solution: Clean the oil filter to remove accumulated contaminants and replace any clogged filter elements; inspect the oil lines for kinks or blockages, and clear and straighten them as needed; check the oil temperature control valve for malfunctions, repair or replace faulty components, and ensure smooth oil circulation.

Q24: Oil circuit pressure is too low, triggering an equipment alarm and protection.

Solution: Top up the lubricant to the specified level; inspect the oil pump for wear and insufficient oil supply, and repair or replace it as necessary; identify and address any leaks caused by inadequate sealing in the oil circuit, seal the leak points, and restore proper oil circuit pressure.

V. Noise, Vibration, and Abnormal Sounds (Clauses 25–27)

Q25: The equipment generates significant noise and severe vibration.

Solution: Tighten the equipment’s foundation bolts and body‑mounting hardware, and adjust the equipment’s level. Inspect the vibration‑isolating pads for signs of aging or damage, and replace any defective components promptly. Check the main‑unit and motor bearings for wear; apply grease to address minor wear, and replace the bearings if wear is severe.

Q26: The machine head emits unusual noises and metallic knocking sounds.

Solution: Immediately shut down the machine for inspection to identify screw wear and abnormal rotor clearance; check the head assembly for foreign debris and loose components, remove internal contaminants, and tighten all fittings; prevent operation without adequate lubrication to avoid dry‑grinding damage to the head; if the fault is severe, disassemble the unit for thorough maintenance.

Q27: Abnormal noise and overheating during motor operation

Solution: Inspect the motor fan blades for looseness or jamming and realign the fan components; check the motor bearings for insufficient lubrication or wear, and service or replace them as needed; verify that the motor is not overloaded or operating with a missing phase, and stabilize the supply voltage while reducing the equipment’s load.

VI. Common Errors and General Faults (Items 28–30)

Q28: Frequent alarms and false fault indications on the air compressor.

Solution: Clean dust and oil buildup from the sensor probes and terminal blocks, and secure all wiring connections; restart the PLC controller and restore the factory default settings; inspect the control wiring for aging or interference, implement shielding to mitigate interference, and replace any aged cables.

Q29: Poor drainage and excessive water accumulation in the gas storage tank.

Solution: Manually open the drain valve to fully discharge accumulated water, and clear any debris blocking the valve; inspect and service the automatic drain device, checking for blockages and solenoid‑valve malfunctions, and repair or replace faulty drain components; adjust the drain frequency appropriately based on ambient humidity.

Q30: Abnormal operation and deteriorated operating conditions after equipment maintenance.

Solution: Verify the model numbers of maintenance parts to prevent the use of non‑standard components; inspect that filter elements and lubricants are properly installed and that seals are tight, then re‑align and reinstall the components; calibrate the pressure and temperature parameters after maintenance, and reset the equipment’s maintenance countdown program.