How to fix and replace your air compressor pressure switch?

How to fix and replace your air compressor pressure switch?
Spread the love

Almost any and all forms of air compressors will have some form of switch that regulates pressure on the device.

What this switch does is indicate to the air compressor when to start and stop. 

There are two distinctions in the pressure switch at which it opens and closes, with the switch closing when it reaches the “cut-in pressure” and opening at the “cut-out pressure”.

There may be certain circumstances where it can become damaged, so you might want to ensure that the switch on your device is in good shape or condition before using your air compressor.

It can essentially come down to the air compressor reaching the end of its useful life but in some cases there can be external cases that interfere with the device and inhibit it from working as efficiently or prevent it from working at all.

How will I know if my air compressors switch needs replacing?

There are a number of problems that indicate a broken air compressor switch. While there are two separate types of air compressor switches, all are mostly universal and the issues that arise include:

  • The air compressor will not turn on despite being powered up
  • The air compressor switch will not twist or turn
  • The unloader valve on the air compressor is leaking
  • The compressors keep pumping up and the relief valve will not shut off

It is relatively well known that the pressure switch on an air compressor will most likely the one item that needs replacement more often than other parts of the device. If you follow some of the criteria mentioned previously, you may be able to determine whether or not your air compressor switch is working or not.

If you are having trouble figuring out the source of your problem, it may be best to seek professional help from a technician.

What criteria should I follow when choosing as my replacement air compressor switch?

Here are a number of different criteria you should follow when selecting your replacement switch:

  • Type of replacement pressure switch
  • The physical connections that are required
  • The electrical load that air compressor
  • The maximum pressure rating
  • The pressure switch has an on/off

First and foremost the most important factor for choosing your air compressor replacement switch is the make and model of your air compressor. You want to get an original replacement switch that fits in with the type of air compressor that you have, as purchasing a cheap replication or different branded switch can cause problems as a result of the difference in air compressor design and production.

There are universal switches though such as the: 

Air Compressor Pressure Switch Control Valve 90-120 PSI 240V

Tying in with the previous point of selecting a switch that is similar to the brand and model of your air compressor, different compressors can have different sizes in the physical connections of which you install your pressure switch. You can choose to install an adapter but this can be slightly more complicated and it is much easier to purchase one with correct fittings.

Your pressure switch needs to be able to handle the motor currents of your air compressor, and whilst this is not a problem if you’re purchasing an original and similar design pressure switch, if you choose on your own then you must ensure it fulfils this criteria.

All air compressors reach up to a certain maximum pressure, with the switch required to reach that amount of higher. Purchasing a lower pressure switch would cause more problems and result in further complications. You should also ensure that you never set the pressure switch higher than the maximum rated pressure of your compressor.

There are some compressor switches that do not have an on/off switch. Determined by the type of compressor you have, you may need an on/off or a control panel with control buttons.

If your air compressor is large then it will most likely have a control panel, with the smaller ones having a switch. Get something that has this control panel such as the: 

Powermate 034-0197RP Pressure Switch

How do I replace the air compressor switch on my own?

Following these next steps, you can easily replace your pressure switch with your replacement:

  1. Disconnect power and de-pressurize the compressor
  2. Unscrew and remove the unloader valve
  3. Remove all electrical wiring connected to the pressure switch
  4. Unscrew the pressure switch off the compressor (including connector)
  5. Apply Teflon tape to the connector (optional)
  6. Screw the connector into the new pressure switch
  7. Screw in the new pressure switch into the air compressor
  8. Reconnect all the wires to the new pressure switch
  9. Check all connections and ensure they are safe and stable
  10. Reconnect power to the air compressor
  11. Test the new pressure switch

It is important to firstly disconnect the air compressor from the power source, as this will prevent any electrical problems arising as well as ensure your safety when modifying the electrical wiring during your switch replacement.

In all cases dealing with repairs of electrical items you never want live power surging through the device when you handle it.

The optional selection of applying Teflon tape to the connector merely improves the ability to screw it into the pressure switch and the air compressor. Teflon tape creates a strong and durable screw in whilst also helping to prevent an excess of debris from clogging it up. These tapes are affordable, such as the: 

Dixon Valve & Coupling TTB50 PTFE Industrial Sealant Tape

How can I prevent my air compressor switch from breaking or needing replacement in the future?

There are multiple things you can do to improve the life of your pressure switch and air compressor:

  1. Maintain it at least once a year, ensuring all parts work and are clean.
  2. Do not purchase non-verified parts or second hand parts
  3. Do not use your device in an inappropriate manner (ignoring limitations on device, throwing items at it, etc.)


​If you follow the steps shown in this article on how to find a replacement pressure switch, make the replacement and maintain the air compressor, you should have no further problems with the air compressor and continue to use it for the benefit of yourself and others.

About the author

MZB Compressors

Click here to add a comment

Leave a comment: