Hey! This site is reader-supported and we earn commissions if you purchase products from retailers after clicking on a link from our site.

This article will provide you with all the possible reasons as to why your Porter Cable air compressor will not shut down, and Porter Cable air compressor troubleshooting tips to help you resolve this issue, along with existing reader problems and responses.

Table of Contents

Reasons Porter Cable Air Compressor Won’t Shut Off

Here are some of the most common reasons why your air compressor may not be shutting off:

  • Air leaks
  • Broken air gauges
  • Dirty filters
  • Motor problems
  • Pressure switch problems
  • Pressure relief valve failure
  • Underpowered extension cord

Air Leaks

Sometimes, an air compressor will continue to fill the tank after the cut-off level has been reached due to the potential that there is a leak in the system. 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. It may be possible to fix leaks with special equipment.

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.

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. For this reason, you should inspect all filters and change any that need it due to dirt/debris buildup.

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.

Pressure Switch Problems

If for some reason your compressor will not shut off, it could be that you have a faulty pressure switch that is not switching when the cut-out pressure is reached. In some instances, unfortunately, the PRV does not work as intended.

Pressure Relief Valve Failure

If it gets stuck closed and the compressor motor keeps running, worst case the tank could eventually explode. The PRV could also become stuck open, which will prevent the tank from being able to reach its cut-out pressure, causing an air compressor to not turn off. 

Underpowered Extension Cord

It’s possible that the use of an extension cord is hampering 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. The simple solution here is to stop using the extension cord.

Please visit our Air Compressor Won’t Turn Off – Fixing A Compressor That Won’t Stop Running for more details!

Reader Questions and Responses

Porter Cable Air Compressor Not Shutting Off – Porter Cable Air Compressor Troubleshooting

Question

I have a porter cable electric air compressor 150 psi, it turns on but won’t turn off when it’s supposed to and also when it’s running it sounds like it has something in it that rattles not sure if it’s in the motor. do you think you can help me?

Porter Cable C2002 WK air compressor
Porter Cable C2002 model air compressor

Response

When you say that it won’t turn off, are you saying that it runs and won’t stop, and the pressure in the tank keeps rising, or are you saying that it runs non-stop, and the pressure in the tank gets to a certain level (what level?) and won’t go past that.

If the former, you likely need a new pressure switch.

If the pressure won’t rise, wander over to the TROUBLESHOOTING page and click the link to “won’t build pressure” for some tips.

Are you sure the rattle is inside the compressor or something loose on the outside?


Porter Cable Air compressor Won’t Turn Off – Porter Cable Air Compressor Common Problems

Question

Specs:

Porter Cable 150 PSI Max
6-Gallon Tank
2 HP
2.6 SCFM @ 90 PSI

Purchased about two years ago, used about 6 or 7 times, mostly to dust out the computer. I used a nail gun once. Turns on just fine, fills the tank with air and shuts off automatically when the tank is full. The problem is I have not got any pressure to operate the tool or the air gun. Shut off, bled tank, restarted with the same issue.

Response

You are not alone. I get questions about this issue often enough that I wrote a page or so on it.

Please go to the TROUBLESHOOTING PAGE on this site and look for “no air out of hose” for some tips. Thanks.


Porter Cable Air compressor Doesn’t Turn Off – Porter Cable Air Compressor Troubleshooting

Question

Porter Cable CPF23400S-2 doesn’t seem to supply the needed CFM although pressure builds to 135psi … even with a small draw (i.e., regulator spilling air to limit output to 90psi), the pump runs continuously and never gets to 135psi.

When I remove the motor fan cover I can rotate the motor armature and piston cycles very easily … wonder if this is an indication that the piston, sleeve and compression ring need to be replaced.

Response

Steve, it’s possible it’s a pump issue. However, I think it is more likely that you have a leaky intake valve or an internal gasket failure.

Can you feel the air being taken in at the intake port? Is there any air puffing out? If so, your valve is wonky.

Otherwise, if it were my air compressor, and there were no leaks anywhere visible, I’d tear down the pump to check the gaskets.


Porter Cable C2002 Compressor Will Not Shut Off – Porter Cable Air Compressor Common Problems

Question

I have a C2002 porter cable compressor that continues running, I have replaced the check valve, installed a regulator kit and replaced the pressure switch.

If I set the regulator at 80lbs it continues to run past 120 lbs never to shut off.

I always have pressure and it will hold its pressure forever.

When I use it I shut the compressor on and off manually.

Response

Does it run until it blows off the PRV Jim?

Question

Bill,
You asked me if the PRV blows off. No, because I haven’t let it run that long for fear that the compressor could blow up and do damage or injury.

Response

if you pull on the PRV and air comes out, and you push it back in to stop the airflow, it’s a pretty good bet that the PRV will open itself and dump air when the pressure gets to its cracking point. That’s its purpose.

When you say “If I set the regulator at 80lbs it continues to run past 120 lbs never to shut off.” the air regulator has no control over the On/Off of the compressor motor. It’s the pressure switch that does that.

If your air compressor runs and the tank pressure bypasses the cutout setting of the pressure switch, it’s typically a pressure switch failure or improper wiring that’s causing that.

You say you’ve replaced the pressure switch. If it was working, when the tank pressure reached the cutout setting, the switch should trip off. If it’s not the switch itself is likely the problem as long as the tank air pressure reaches and bypasses the pressure switch cut out setting. What is that for your switch, Jim?

Porter Cable Air Compressor Won’t Shut Off – Porter Cable Air Compressor Troubleshooting

Question

Hello,

It started with the regulator hissing and the compressor trying to build as it leaked from the area around the regulator. I carefully inspected the plastic diaphragm and put it back.

Now, it doesn’t seem to leak as bad – YET, now it actually runs to fill the tank till over 155 PSI and then the pressure relief valve blows open, of course.

Where is the whatever component that makes the motor shut off before 155?

I greatly appreciate that this site exists and hope that help on my issue exists.

Ian

Porter Cable C2002 WK air compressor
Porter Cable pancake-style air compressor

Response

This is a C2002?

The pressure switch is under the cover, near the power switch on a bracket with a hose to the manifold (or possibly the tank, can’t tell for sure). If that came off or is leaking, you’ll have this symptom. Item 111 on the parts list.

Question

Hi.

I’ve swapped out several parts:

On my 6 gal C2002 (type.7), I have carefully checked the plastic diaphragm for leaks, changed the safety valve (4) “pressure relief valve”, and changed the pressure switch (111) ——-
YET, the NEW safety valve blows at 145-155. The NEW pressure switch does not seem to cut the engine off.

Any idea what is going on?
Anybody?

I’m really glad this site exists.

Response

What are the settings – the cut-out and cut-in pressures settings – on your new switch?

If the compressor tank pressure bypasses the cut-out pressure setting and the PRV lets go, then either the switch is faulty or it’s been installed improperly.

First thing though, do you know what the settings are supposed to be?

Question

Hello!
Thanks for your response!
Yet, I’m still stumped, because the cut-in and cut-out settings on my pressure switch are …. not simply listed….. yet they were exactly designed as replacements for the C2002 150psi type 7 Porter Cable pancake compressor?

And if I installed it improperly, …. how?

As it’s a tube and switch with only two holes to attach, would it either work, pinch, leak, or be hooked up backwards? I don’t know what other option for incorrect installation would be.

Maybe it’s time to get a different brand of compressor than Porter Cable?

Sorry, I’m frustrated.

Response

Ian, according to the specs the PORTER-CABLE C2002 0.8 HP 6-gal 150 PSI Pancake-Tank Electric Air Compressor by Porter Cable is supposed to shut off at 150 PSI.

If your PRV is letting go at 155 PSI, and I expect that the gauge accuracy on these cheaper compressors is always suspect, I surmise that your air compressor is not reaching the pressure necessary for the pressure switch to stop the power supply to the motor and that it’s the PRV that is the problem.

I would be inclined to push in on the end of the PRV when it starts to release air and let the compressor run up to 160 PSI and see if it shuts off by itself. Typically PRVs let go after reaching pressures higher than 5 PSI over the set point. I’d be comfortable watching the pressure get to 160 before letting the PRV release.

If the pressure gets to 160 PSI and the compressor doesn’t shut off, then it’s got to be a bum pressure switch as far as I’m concerned.

Response

Hmmm. One thing at a time.

Let’s try a diagnostic:

Unplug the machine and then disconnect one of the wires that go to the pressure switch. Tape or cover the wire so that it doesn’t touch anything, and then plugin again.

Does it run?

whether it runs or not, unplug and reconnect the first wire and disconnect the other wire in the same way, and plugin again.

Does it run now?

It should not run either way. If it does, there is a short in the wiring other than the switch.

If it does NOT run, then the wiring is correct, and the pressure switch is bad, or wrongly rated.


If you have any questions regarding why your Porter Cable air compressor will not shut off, please leave a comment below, with a photo if applicable, so that someone can help you!