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This article will provide you with all the possible reasons as to why your DeWalt air compressor will not shut down, and DeWalt air compressor troubleshooting tips to help you resolve this issue, along with existing reader problems and responses.
Table of Contents
Reasons Husky Air Compressor Won’t Shut Off
Here are some of the most common reasons why your air compressor may not be shutting off, summarized in the table below with some tips!
|Air leaks||You must confirm whether or not there is a leak by listening for hissing sounds around the whole system or looking for holes on the side of the tank.|
|Pressure switch problems||It could be that you have a faulty pressure switch that is not switching when the cut-out pressure is reached. Replace.|
|Pressure relief valve failure||If the PRV gets stuck closed, worst case the tank could eventually explode. The PRV could also become stuck open, preventing the tank from being able to reach its cut-out pressure.|
|Underpowered extension cord||An extension cord may hamper your air compressor’s performance, blocking it from being able to reach the cut-out pressure and thus causing the air compressor to not shut off.|
|Motor problems||If the pressure inside your tank rises but then stops before it reaches the set cut-out pressure, but your compressor motor continues to run, then it is more than likely that you have a problem with the compressor pump itself.|
|Dirty filters||It’s possible that your compressed air system’s filters are becoming clogged, affecting airflow and leading to your air compressor not shutting down.|
|Broken air gauges||A broken air gauge is another common problem that could cause an air compressor to not turn off. When it’s working, the pressure gauge will steadily rise until it reaches the compressor’s cut-out setting.|
Please visit our Air Compressor Won’t Turn Off – Fixing A Compressor That Won’t Stop Running for more details!
Additional DeWalt Pages
- DeWalt Air Compressor Won’t Start
- DeWalt Air Compressor Won’t Shut Off
- DeWalt Compressor Oil – Choosing Oil, How Much To Use & Changing Oil
Reader Questions & Responses
DeWalt Air Compressor Will Not Shut Off – DeWalt Air Compressor Troubleshooting
It will not shut off at 180 psi anymore.
The pressure switch off/on (auto) selector dial has not been working for a while, would just leave it in the on/auto position then just unplug it when done.
Been working a while this way but recently stop shutting off at 180 psi.
I would have to unplug the power to get it to stop. It has gotten to 210 psi before I shut down.
While troubleshooting found that one of the hose couplers on the unit was leaking so replaced it, still got an issue.
Since had I had a problem with the pressure switch I replaced it.
The unit still will not shut off.
Next, let all air out of the tank then refill till both pressure gauges showed 150 psi. Left sitting overnight for 12-15 hours to see if had a leak anywhere. Both gauges still had 150 psi (one was showing 146 but felt this was ok).
Was going to spray all lines and fittings with soapy water to see if I had a leak but not sure if I need to now.
Anyway, I am stuck as to what my next troubleshooting steps should be. Can anyone help me out, please?
When you use your multimeter to check the power, is power still flowing from the pressure switch to the motor side even when the tank pressure rises past the normal cut out?
If yes, and assuming that the pressure switch is set to cut out at 185 PSI, then either the switch is pooched, or it’s wired wrong.
If the pressure switch is working, if it’s wired correctly, and if the pressure cut out is 185 PSI, when the tank pressure reaches +/- 5 PSI of 185 PSI the pressure switch will shift to non-passing (trip off), and power will no longer flow to the motor, stopping it.
At this point, the tank pressure will no longer rise.
That pressure switch (a21107) appears to be set to 200PSI.
The model appears to be a 4.5 (as opposed to a 2.5) gallon tank.
The tank seems to be rated around 250PSI with 225PSI safety.
The range on the pressure switch is supposed to be +/-10%, so that’d be 180 to 220PSI, just short of the safety valve rating.
So, since replacing the pressure switch, have you let it run up to 220 or whatever the safety valve allows?
My bad typo it is a 4.5 gal unit
Yes tank rated at 200 psi
Unit best I remember, always shut off at 180 psi
But at 180 or 200 it still does not shut off. One time I let it run up around 220 before unplugging. I do know for a fact that it has never run above 200 until recently.
I am sure the pressure switch is wired correctly.
Doing this from memory
Only 2 ground screws on each side of the switch
One wire from both sides of the switch tired together (idiot-proof due to connector type)
2 other wires that are hard to get crossed due to length
BUT when you take about 15 pictures with your iPhone prior to disconnecting it is hard to wire switch wrong.
Have not checked the power reading with the meter but will check and update
Thanks for feedback
DeWalt Air Compressor Will Not Stop Running – DeWalt Compressor Troubleshooting
It worked fine for about a year until the warranty expired, then it started acting up. When the compressor hits 150psi, it keeps pumping, subsequently blowing the relief valve, and filling the tank again, over and over and over again. I looked for an adjustment screw, thinking it may have vibrated loose, but have yet to find one. Am I missing something? Thanks for the help!
Your air compressor symptoms suggest a pressure switch failure.
The pressure switch should toggle the power supply to the air compressor motor to OFF when the pressure in the tank reaches the normal cut-out pressure.
I wouldn’t use this compressor again until I replaced the pressure switch.
DeWalt Air Compressor Will Not Shut Off – DeWalt Air Compressor Troubleshooting
I have an air compressor that reaches the set air pressure of 90 pounds, however, the compressor itself does not shut off and continuously sucks air.
Is this an issue with the regulator?
I’m assuming it’s most likely a valve of some sort. I looked at a parts list and it looks like the manifold assembly is discontinued, what is the OEM equivalent?
Thanks ahead of time
If the air pressure in the tank gets to the normal cut-out pressure setting, and the compressor does not shut off, then that typically is a problem with the pressure switch.
If the pressure in the tank never gets to the normal cut out, and the compressor runs and runs, then that typically points to the pump being the problem.
Since this compressor normally has a cut-out setting of 200 PSI, and I infer from your post that the pressure is only getting to the 90 PSI level, you most likely have a compressor pump problem.
If I have misinterpreted what you have written, please clarify with a comment here.
To put it another way, does the tank gauge also stop rising at 90? That’s the one on the left.
If it keeps rising, let it go until it stops increasing – around 200 is normal. If it doesn’t then shut it off, you have a problem. If it does stop, then it’s operating normally.
Thanks for the response and I’m sorry for the delay. The pump continues to run but the needle stops at the set pressure of 90 psi. I checked this model a little more and other pumps and I see the pressure switch is a common issue as I see is suggested in the response.
I ordered a pressure switch for the pump but after ordering I saw there is a valve of some sort as well (brass not polymer like in the pressure switch).
John, if the tank gauge stops at 90 PSI, and the compressor continues to run, as it says below, it’s not likely the pressure switch, but the pump itself that is the problem.
If you’ve already ordered a pressure switch I’ll bet you end up with a spare, as the one you replace may be fine.
I’m sorry, I don’t understand “I saw there is a valve of some sort as well (brass not polymer like in the pressure switch). “. Is there a question here?
Based on what you are saying it looks like I’m going to have a spare. But regarding the brass valve, I watched a rebuild for this model and they cited the brass valve as a potential issue as well. I’ll take the input from the people that know more than i.
I guess it may be better to invest in another compressor if it’s cost-prohibitive.
John, it would be good if you could tell me the name of the valve, or what they call it.
If it’s the unloader valve, typically there is either one on the side of the pressure switch (maybe plastic but more often brass) or, if the switch has the unloader internally, the line will insert into a quick fitting on the bottom of the pressure switch.
This valve – if the unloader, will have nothing to do with the run-on compressor UNLESS the tank check valve is compromised. Then, air will leak out of the tank continuously when the compressor stops.
Please take the time to read about the various compressor components that are explained in great detail on this site, along with the many troubleshooting pages which are written for folks just like you; struggling with an air compressor problem.
First, thank you for the comments and help. I did replace the pressure switch and I also looked closer and realized their regulator was leaking. I was able able to clean the parts and lube the O rings and no leaks.
The compressor now reaches 210 and shuts off.
If you have any questions regarding DeWalt air compressors not shutting off, please leave a comment below with a photo if applicable so that someone can help you!
I have the same problem as Jim. My D55146 compressor won’t continue running. I have replace the pressure switch but the problem remains.
Does it sound like it’s lugging down, or just stop suddenly?
Was it working under the present conditions previously? That is, same outlet, etc.?
It only turns the piston over about one time then stops running. Sometimes if I leave the switch on it will try to start again with the same result. That acted like a loose connection or wire so I checked all wiring connections and checked and changed outlets. Same results except now it doesn’t even turn over at all.
Well, maybe you should recheck that it’s getting power.
Other than that, it may be you have a weak start capacitor, so you can check that.
If that’s not it, you may just have a bad motor.
OTOH, apparently some of these, like the type 2, have a brush motor, so if that’s the case with yours, it’s probably the brushes. Rotating the motor by hand (with power off) and trying it again will tell you it’s the brushes if it tries to start again.
Thanks for all of your suggestions. I had a person that repairs electric motors look a it and after measuring motor output with an ohm meter, he determined that the motor is bad.
We are having the same issue, replaced switch did not help, only difference we have is it doesn’t seem to go past 145lbs but keeps running, when we shut it off there doesn’t appear to be any leaks. any idea’s
No static leak is good.
But that the pressure stops increasing says there’s probably a leak by the piston or head (gasket). Could also be a leak between the head outlet and the tank.
For clarity, it is the pressure getting to cut-off pressure that makes it stop. If it never reaches that pressure, it will not stop unless it burns up or trips out the motor.