I have a 2hp 20gal Campbell Hausfeld, it builds air just fine but after I start using it the motor try’s to crank back up but barely turns over a few times then nothing.

I have to let the air out and wait a few minutes and start all over.

Smaller Campbell Hausfeld air compressor
Smaller Campbell Hausfeld air compressor


Friend, I have uploaded an image of a new Campbell Hausfeld air compressor. If yours is different than the compressor shown, how about uploading a photo or three of yours?

The key thing you’ve written is “I have to let the air out and wait a few minutes and start all over.”

If you have to let the air out for the compressor for it to restart, that indicates that the compressor hasn’t got enough power from the motor to overcome the start procedure, or there is enough air trapped over the piston to increase the start load beyond the capability of the compressor motor.

This air compressor symptom is typically related to a problem with the unloader valve not working. The unloader’s job is to vent any air over the piston when the compressor stops, reducing the restart load.

Please empty the tank, start the compressor, and check the unloader valve operation, will you? If you aren’t sure what the unloader is, there’s a page on this site with complete details.

Or, the compressor start problem could be related to the compressor power supply.

If you are not using an extension cord or power bar, if the socket into which the compressor is plugged is working, if the amperage of the socket power is 20 amps (better than 15 for compressors), you’ve check and the compressor the unloader valve works, then it’s time to look to the possibility of a failing start capacitor being the issue.

If you are not sure what the capacitor is and does, there’s a page on this site that describes it, and another that tell how to spec and buy a new one.

New comment? New question? Please add it here along with photos to help others help you with your compressor and equipment problem!