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Clarke air compressors not starting appears to be a fairly common issue with Clarke compressor users. This article will provide all the relevant information on why your Clarke air compressor may not be starting!

Table of Contents

Clarke Air Compressor Will Not Start – The Possible Reasons

The reason your Clarke air compressor is not starting could be down to any of the following reasons:

  • Power issue
  • Faulty fuse or breaker
  • Tank full of air pressure
  • Pressure switch problem
  • Faulty unloader valve

Clarke Compressor Power Issue

The first check is to ensure that the Clarke compressor is plugged into the wall properly and not an extension cord. You should avoid using power bars and power strips with your Clarke compressor because they will not support the direct connection of machines to electricity sources. 

If your Clarke compressor is one of the models that come with an ON/OFF switch, either separate from or part of the pressure switch, please make sure that it is switched on.

Clarke Compressor Faulty Fuse or Breaker

It may be that the breakers or fuses are blown inside of your electrical service panel. You may need to reset the circuit breaker or change the fuse to get your Clarke compressor to start. It’s possible that your Clarke compressor is creating an electrical fault, and as soon as you got to start it, the breaker is tripping or the fuse is popping. If you have a thermal reset button on your Clarke compressor, it is worth giving it a push.

If the Clarke compressor still persists to fail to start, it could be a start capacitor issue, a pressure switch issue, or even a motor issue. Visit our Air Compressor Troubleshooting, Solutions, Common Problems & Causes for more information.

Clarke Compressor Tank Full of Air Pressure

The next check for the Clarke compressor is whether the tank is full of air pressure or not. If the pressure inside the Clarke compressor tank is above the cut-in pressure of the pressure switch then there will be no power flowing to the Clarke compressor motor, therefore the motor will not start.

It’s important to always drain the Clarke compressor tank of air after every use, and if necessary, before use. Not only may it block your Clarke compressor from starting but it may also allow for moisture build-up – another problem in itself. For more information visit our How Often To Drain Air Compressor Tank guide!

Clarke Compressor Switch Problem

You can check the Clarke compressor pressure switch by unplugging the compressor from the wall outlet and draining the air from the tank. Take the cover off the pressure switch and have somebody else plug the compressor back in and turn it on as you listen for a click sound that will indicate the pressure switch is working.

If you have a multimeter, you can then check to be sure that power is actually flowing across the pressure switch to the motor circuit. This may help you diagnose where the problem lies – if it is the pressure switch! For more information, visit our Air Compressor Pressure Switch Troubleshooting & Buying Guide!

Clarke Compressor Unloader Valve

If the unloader valve on your Clarke Compressor does not operate as it should and is stuck in a closed position, that may be why your Clarke compressor will not start when the pressure switch sends power to the compressor motor. If your unloader valve is the issue, it is recommended to get a replacement valve and install it in the correctly aligned position. Visit our Air Compressor Unloader Valve Explained, Adjustment & Common Problems guide for further information!

FAQs (Frequently Asked Questions)

How do you reset a Clarke air compressor?

The process to reset your Clarke air compressor is simple, first of all, give your compressor enough time to cool down, typically around 5-10 minutes. Once your Clarke compressor is cool, you can press the reset button before attempting to turn the compressor on again.

Do Clarke air compressors have fuses?

Depending on the model, some Clarke air compressors will have reset switches while others will have in-line fuses that need to be checked. To find them follow the line of power from the Clarke compressor back to the outlet. If you find a blown fuse or tripped breaker go ahead and either replace the fuse or reset the breaker. In other cases, it may be that the Clarke compressor is blowing a fuse in the wall socket due to a number of reasons like using an extension cord.


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