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by Don
(Spokane, WA)
It’s a CENTRAL PNEUMATIC AIR COMPRESSOR 2 HP-8 GALLON model 40400
I need to know what to do when the compressor doesn’t start?
Hello Don. Nice to hear from you.
A few questions and observations:
-are you sure you are getting power?
-if you have an on/off button, is it set to on?
-do you have a re-set button on your motor? If so, push it.
-is the pressure in the tank below the cut-in pressure of your pressure switch?
These are just a few of the things to check.

Won’t start
I have power with and without an extension cord. On switch is on. The reset button won’t start the motor.
I drained the tank from the screw below to make sure there is no humidity inside. Last use I had to drain the tank just to get it to start.
In order for the compressor to start, electricity must flow through the pressure switch to the motor.
If all conditions are “calling for power”, and the compressor motor doesn’t start, and you have made all the checks to make sure there isn’t another issue preventing the start, then the next check is to be sure that power is actually getting through the switch to the motor, and you need to look at the pressure switch at this point.
If power isn’t flowing across the switch with the tank empty of air, it’s likely the switch.
If power is flowing across the switch, and the compressor is cold, make sure power is getting across the reset switch. They sometimes fail.
Let us know what you’ve found, will you?
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I have a Model 40400 central pneumatic air compressor and it won’t start. Some models have a reset button, if mine does, I do not know where it is. Secondly, if it doesn’t have one, what is the reason that mine won’t start. Just for information, it is plugged in, the circuit is good and the off/on button works.
Bill, should this page not be under here?
https://about-air-compressors.com/central-pneumatic-model-40400/
Then Ruth would have seen the manual, probably.
Yup. It’s just that once there’s a thread, it’s a witch to move to another page. Will get to it in time though. Cheers.
Yeah, it has one, but I can’t see it in any of the pix. Get the manual here – maybe it will give you a clue…there’s a drawing, but doesn’t really show where the reset is.
You say the off/on button works – how can you tell?
*Oh! Found it. Face the front of the machine, look on gauge side – follow the handle to the end – it’s just below the last handle screw.
Oh hhhhhhh! Thanks, I found it! This was much clearer than the booklet.
You noticed that huh?
?
So, is it working now?