Why Your AC Compressor Is Malfunctioning

25 March 2020
 Categories: , Blog


The air conditioner (AC) compressor works by compressing the refrigerant to a high pressure and temperature. The high pressure allows the refrigerant to flow, and the high temperature facilitates heat exchange. Both processes are necessary for cooling. Thus, your AC won't be able to cool your house if the compressor is not working as usual. Below are some of the things that might interfere with a compressor's work.

Wrong Settings

A wrong compressor setting will prevent the compressor from running. The compressor only runs if you need active cooling and have set your thermostat to 'cool.' Here are some of the situations that can cause a compressor to stop:

  • You forgot to set the thermostat.
  • Your programmable thermostat has the wrong date and time.
  • The thermostat has malfunctioned.
  • A nearby heat source is causing erroneous thermostat readings.

Thus, the thermostat should be your first stop if the compressor is not running. Confirm that the thermostat is operational and properly set.

No Power

The compressor needs electricity to run, so it will be off if the system is not getting power. This will be the case if:

  • Your house is experiencing a power blackout.
  • The AC's breaker has tripped.
  • The AC's fuse is blown.
  • Someone or something has unplugged the AC's electrical cable.

Therefore, you should confirm that the AC has power if the compressor is not working but the thermostat is properly set and operational.

Electrical and Electronic Malfunctions

Various electrical and electronic malfunctions can also stop the compressor's malfunctions. Here are two classic examples of such malfunctions:

  • A defective start capacitor. The start capacitor provides the power boost necessary for the compressor motor to start running.
  • A defective start relay. The start relay is an electronic switch that gets the compressor motor running.

The electrical or electronic parts of your compressor or AC are not good candidates for DIY repairs or service. The risk of damage or injury is too high. Consult a professional AC technician if you suspect such technical problems.

Dead Compressor

Lastly, your compressor might not be operational simply because it is dead. The compressor might die due to these issues:

  • Prolonged overheating
  • A serious electrical malfunction that kills the motor
  • Extreme physical damage
  • Accumulation of wear and tear due to aging

The only solution to a dead AC compressor is to replace it.

The above problems show that not all problems with the compressor are complicated. A diagnosis will help you figure out the nature and extent of the problem with the compressor so you can fix it.

For further questions about your central air conditioner, talk to a professional near you.