6
Oilless Compressors
Troubleshooting Chart
Symptom
Possible Cause(s)
Corrective Action
1. Switch in OFF position
2. No electrical power at wall outlet
3. Compressor has reached automatic
shut-off pressure
4. Motor overheated
5. Loose electrical connection
6. ON / OFF switch bad
7. Pressure switch bad
8. Defective motor
1. Lack of proper ventilation/room
temperature too high
2. Excessive air usage, compressor too
small
1. Open tank drain valve
2. Loose connections (fittings, tubing,
air hose, any connections, etc.)
3. Tank leaks
1. Excessive air usage, compressor too
small
2. Open tank drain valve
3. Loose connections (fittings, tubing,
air hose, any connections, etc.)
4. Pump wore out
1. Excessive water in tank
2. High humidity
1. Defective pressure switch
2. Defective safety valve
1. Make sure compressor is plugged in and switch is ON
2. Check circuit breaker or fuse at electrical panel.
3. Release air from tank until compressor restarts
automatically
4. Allow compressor to cool for approximately 30
minutes so thermal overload switch will reset. Make
sure compressor is run in a clean, well-ventilated area
where temperature will not exceed 100°F.
5. Check all electrical connections
6. Replace ON / OFF switch
7. Replace pressure switch
8. Replace pump / motor assembly
1. Move compressor to a clean,well ventilated area
where temperature will not exceed 100°F.
2. Decrease usage or purchase unit with higher air
delivery (SCFM)
1. Close tank drain valve
2. Check all connections with soap and water solution.
If a leak is detected, tighten. Or remove fitting and
apply pipe tape to threads and reassemble.
Do not disassemble check valve.
With air in tank, bleed tank first.
3. Check entire tank for leaks with soap and water
solution.
1. Decrease usage or purchase unit with higher air
delivery (SCFM)
2. Close tank drain valve
3. Check all connections with soap and water solution.
If a leak is detected, tighten. Or remove fitting and
apply pipe tape to threads and reassemble.
4. Replace pump / motor assembly
1. Drain tank, tilt tank to remove moisture
2. Move to area of less humidity; use air line filter
1. Replace pressure switch
2. Replace safety valve with genuine replacement part
Compressor will not run
Thermal overload
protector cuts out
repeatedly
Tank pressure drops
when compressor shuts
off
Compressor runs
continuously / air
output lower than
normal
Excessive moisture in
discharge air
Safety valve pops open
