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Air compressor troubleshooting chart

Look up likely causes, what to check, and remedies from the symptom. Your machine's instruction manual always takes priority for inspection and replacement intervals and oil types. The intervals here are examples for models found in public documents and vary with running hours, ambient temperature, and dust. Never remove a safety valve or raise its setting. Leave dryer refrigerant, disassembly and overhaul of the main unit, and electrical work to the manufacturer, a dealer, or qualified personnel. The key points of the laws were checked on e-Gov on 2026-10-06

Insufficient discharge volume or pressure (pressure does not rise as usual)Common

Consumption on the user side, intake filter, piping leaks, pressure gauge and pressure switch settings^[1][7]

Likely cause	What to check	Action
Air consumption exceeds the discharge volume (including air leaks)	Leak rate with the ends closed; air required by the connected equipment	Fix the leaks. If that is still not enough, consider adding or replacing a compressor^[1][2]
Clogged intake filter	Dirty filter	Clean or replace it^[1][3][4]
Solenoid valve fault, intake valve not opening fully, clogged separator element (screw)	Load/unload switching; separator replacement interval	Replace the solenoid valve. Replace the oil, oil filter, and separator. Have the manufacturer inspect the intake valve^[1](1 source, for reference)
Worn piston rings or valves (reciprocating)	Whether the tank fill time has lengthened; piston ring thickness	Replace when the wear limit is reached (ask the dealer or manufacturer)^[5][6]

High discharge or unit temperature, or shutdown on abnormal temperatureCommon

Room temperature and ventilation, dirty cooler, oil level^[1][3]

Likely cause	What to check	Action
Insufficient cooling air (poor ventilation, recirculating exhaust)	Compressor room temperature; blocked intake and exhaust openings; exhaust duct	Improve ventilation and keep the cooling air from recirculating^[1][8][9]
Dirty oil cooler or air cooler	Dust on the fins	Clean the fins. For clogging inside the cooler, ask the manufacturer^[1][3]
Low oil level	Oil level gauge	Top up with genuine oil^[1][10]
Deteriorated oil, clogged oil filter, faulty temperature control valve	Oil and filter replacement intervals	Replace according to the replacement guide^[3](1 source, for reference)
Water-cooled: cooling water too hot, insufficient water flow, scale in the water circuit	Cooling water temperature and flow	Increase the water flow and clean the water circuit and cooler^[1](1 source, for reference)

Water appears in downstream piping and equipmentCommon

Auto drain discharge, dryer alarm and dew point, tank drain^[3][1]

Likely cause	What to check	Action
Clogged or faulty auto drain (drain trap)	Whether condensate is coming out; the filter and float valve	Disassemble and clean, and replace if necessary^[3][1]
High dryer dew point (high intake or ambient temperature, exceeding capacity, low refrigerant, dirty air cooler)	Dryer inlet temperature, room temperature, throughput	Bring temperature and throughput within specifications. Leave the refrigerant to the manufacturer^[1][3]
Air tank has not been drained	Tank drain valve	Drain it every day. Fit an auto drain^[11][7]

High oil consumption, or oil in the compressed airScrew

Likely cause	What to check	Action
Deteriorated or clogged oil separator element	Separator replacement interval	Replace the separator. If a specific purity class is required, add a line filter^[3][7]

Safety valve blows under load; does not unloadScrew

Discharge pressure setting, safety valve set value^[1]

Likely cause	What to check	Action
Fault in the safety valve, intake valve, or minimum pressure valve, or a failed solenoid valve	Pressure set values	Replace the solenoid valve. Have the manufacturer inspect the valves^[1](1 source, for reference)
Clogged oil separator element	Replacement interval	Replace the oil, oil filter, and separator^[1][3]
Blockage from frozen dryer piping	Refrigerant circuit; dryer intake and exhaust conditions	Have the manufacturer inspect the refrigerant circuit. Do not attach an intake duct to the dryer exhaust port^[1][9]

Burning smell, discharge piping abnormally hot (sign of ignition from carbon deposits)Common

Likely cause	What to check	Action
Carbon deposits from the lubricating oil built up in the separator and piping, and reaction heat accumulated	Oil replacement interval; the oil in use (genuine or not); the inside of the piping	Stop immediately and have the manufacturer inspect it. Use genuine oil and keep to the replacement intervalsIf it gets worse it ignites and, in the worst case, explodes (JSIM)^[7][10]

Will not start, or stops while running (overload)Common

Power supply and breaker; overload relay indication^[1][8]

Likely cause	What to check	Action
Motor overload relay or thermistor tripped, wrong phase sequence, broken wiring	Controller display; phase sequence	Reset an overload only once; if it recurs, contact the manufacturer^[1](1 source, for reference)
Insufficient power supply capacity, voltage drop, phase imbalance	Breaker capacity; voltage drop at start-up	Use a breaker of sufficient capacity. Keep temporary voltage drops within −10 %. If voltage fluctuation or phase imbalance is large, install an AC reactor on the power supply side^[8](1 source, for reference)

Air tank ruptured (lessons from accident cases)Common

Likely cause	What to check	Action
Pressure above the tank's strength was applied because the safety valve was removed or poorly maintained, or the pressure regulator failed	Safety valve operation; pressure switch operation; the tank's inspection stamp and specification sheet	Use a tank that passed inspection, and inspect the safety valve and pressure regulator regularly. Never remove a safety valve or raise its setting^[12][13](1 source, for reference)
A tank built in-house without strength calculations (it is a Class 2 pressure vessel but did not go through the structural standard or inspection)	Whether any tank has been built or modified in-house	Even for a tank used within your own company, if it falls under Class 2 pressure vessels, use one built to the structural standard that has passed individual inspection^[14][13](1 source, for reference)

Causes on the side of machining conditions and tools are covered in the Machining Troubleshooting Encyclopedia .

📚Sources

Items without a mark are those on which two or more materials from different publishers agree. Values and intervals are governed by each machine's specifications. The text is summarized in Kezuriba's own words.