Central Air Conditioning Compressor Not Working?

There’s a reason why 73% of Australian households use some form of air conditioning – we all know how relentless the summer heat can be! That’s why the last thing you want is to discover your central air conditioning compressor is not working. 

An integral part of an AC system, the compressor applies energy to the refrigerant so that it can continue to circulate. In other words, your air conditioning will come to a halt if this unit fails to do its job. 

If you’ve noticed that your air conditioner isn’t working, there’s a high likelihood that there may be an issue with its compressor. Below, we break down the critical role of this component and the most common reasons behind its malfunction.

What is an air conditioning compressor?

Three primary mechanisms work together within an air con system to alter the state of refrigerant and cool your building: the evaporator, condenser and compressor. 

Responsible for a particularly important stage in the cooling process, the compressor converts low-pressure vapour refrigerant from the evaporator into high-temperature, high-pressure gas that can be pumped through to the condenser. If the compressor fails to operate, this process cannot begin and all subsequent stages in your air conditioning system cease to function.

Reasons why your central air conditioning compressor is not working

Blown fuse or tripped breaker

If you suspect that your compressor isn’t working, the first step is to check that this unit is still receiving power. 

Your compressor is powered by a disconnect, which is a small electrical panel fuelled by your building’s main electrical panel. The disconnect comprises two 120V fuses. If one of these fuses blows, the compressor will not have sufficient electricity supply to turn on.

Alternatively, a breaker may have been tripped. Your compressor will shut down automatically as a way to protect against excess amperage. Whether it’s a short circuit or failed motors, the unit will not function until the root cause of this trip has been resolved. 

It might be time to call in an electrician if you notice that these issues are a regular occurance, as frequent stopping and starting can seriously damage your air conditioning system.

Old or overused capacitor

The capacitor supplies the power required to run your compressor, blower motor and outer fan, with the starter relay transferring this energy. 

Therefore, capacitors and starter relays are fundamental to compressor operation – and the most common source of its issues. Hear humming sounds coming from a malfunctioning compressor? This is likely the unit attempting to access a capacitor that is out due to age or overuse.

The bright side? These elements are generally the most affordable and straightforward to replace.

Clogged filters and dirty coils

If too much dirt builds up in your system’s filters, it can block airflow to the point that the evaporator coil stops working and your compressor is put under so much pressure it overheats. 

That’s why it’s so important to clean coils, replace air filters, and remove any debris in the supply vents regularly. Otherwise, your compressor may end up needing to be replaced. 

Broken valve

A broken valve can result in refrigerant entering the compressor inlet in liquid rather than gas form. In this case, the compressor may still remain operational but the air conditioner won’t cool air to create that comfortable temperature you’re after. Replacing the broken valve will usually fix this issue. 

Need a professional to repair your central air conditioning compressor?

When it comes to fixing an air conditioning system, a standard homeowner with no specialist training is often unable to troubleshoot the issue safely or effectively. In many cases, it’s best to leave repairs to the professionals!

Thankfully, the expert technicians at New Age Air Conditioning are available to help you get to the root of your AC problem. Simply call us on 02 4956 5888 or complete our online form to organise your air conditioning repair today.

Get a FREE Quote*

  • Contact Information

  • Enquiry

  • House Plans

    Upload your house plans if available.

  • Max. file size: 32 MB.
  • NOTE: We will never sell or share your information with a third party.