Air conditioning should be serviced regularly to ensure it runs efficiently, its life is prolonged, and costly repairs and replacements are avoided. This is the case with any unit, including split systems, ducted air conditioning and wall-mounted models.

But what are the benefits of regular maintenance? And is it necessary to service AC every year?

Benefits of regular AC servicing

The main benefit to regular servicing is being able to discover and fix small problems before they become expensive. Regular servicing will also:

  • Improve the unit’s efficiency – regular maintenance will allow your air conditioner to work more efficiently by reducing the pressure and stress that debris and dust build-up can place on your unit. When air filters become dirty and clogged, the normal flow of air is impeded. This means the unit needs to work harder than it should. When dirt or dust covers the evaporator coil, its ability to absorb heat is also impaired, which further reduces its ability to cool your home.
  • Lower your electricity bills – in many households, air conditioning makes up a significant portion of your monthly electricity consumption. Units that aren’t serviced regularly consume more power because they are forced to work harder, and their operating costs increase. In fact, they can use 5-10% more electricity if compromised.
  • Minimise future repairs or avoid a replacement – air conditioners that aren’t maintained properly will eventually lead to bigger problems and potentially a breakdown. As units gather more dirt and dust, they become increasingly harder to clean. And they may become prone to overheating as the evaporator coils won’t be able to dissipate heat effectively.
  • Ensure better indoor air quality – air conditioners don’t just cool and heat your home. They also play an essential part in keeping the circulating air in your home healthy and clean. A dirty unit provides the ideal environment for the growth of bacteria, fungi and mould. When you turn on your unit, these particles blow into the room and contaminate the air. These particles can trigger asthma attacks, exacerbate allergies, and increase the risk of respiratory infections.

DIY servicing

You can do some maintenance yourself. The timing of this will depend on what’s required, and the type of unit you own. You should also follow your unit’s instruction manual carefully, always using the filters recommended for your particular model. If you have misplaced your manual, they are generally available for download on the manufacturer’s website. As a general guide:


Air conditioners should never run without a filter or filters, as they prevent debris and dust from building up on your unit’s internal components. In terms of maintenance, they should be cleaned and/or replaced twice a year. If you live in a dusty location or notice a significant drop in performance, you may need to perform maintenance more often. Also, the more you use your unit, the more often you should clean the filters. If you mainly use it in summer, clean them in spring, so your unit is ready for the hottest part of the year, and again when the weather cools down in preparation for winter.

To clean filters, turn the unit off at the wall first, and then pop open the plastic cover to remove the filter/s. Some models also have an air purification filter that can be removed and cleaned — follow the instruction manual carefully for this. You should clean filters in the outdoor unit with a clean, sturdy brush. For a more thorough clean, give them a vacuum and use the appropriate brush head if it has one. If they are very grimy and dirty, wash in warm water with some mild detergent and then rinse clean. They should be completely dry before you put them back in the unit. Lastly, wipe down the indoor unit’s interior and exterior and any vents or ducts with a soft, damp cloth.


Some systems will also allow you to remove the indoor unit’s louvres, which are the oscillating blades that direct the airflow. If applicable, give them and the space behind them in the unit a thorough clean with your vacuum cleaner or a clean cloth. Again, make sure you’ve turned the unit’s power off before proceeding.

Outdoor unit

The outdoor unit should be cleaned annually. The compressor should be kept clear of obstructions like surrounding plants and grass, and vegetation, dust and cobwebs removed with a brush.

Professional servicing

Professional technicians have the right tools and knowledge to fix or upgrade your system so that it continues to run efficiently. They will also address any issues before they become larger problems. Most air conditioning manufacturers recommend your air conditioner be serviced annually, and a service usually includes your technician:

  • Testing the thermostat
  • Checking the refrigerant gas levels
  • Making sure all the internals are in good condition
  • Cleaning the condenser and evaporator coils
  • Checking and tightening the electrical components
  • Flushing the drains
  • Checking, cleaning and/or repairing the ductwork

However, you should also book in a maintenance call if you notice any of these signs:

  • Reduced airflow – a reduction in airflow is often a sign of a severe problem. It could be due to a blockage, a compromised filter or filters or a compressor that needs replacing.
  • Blowing hot air instead of cold – if your system regularly starts producing warmer air when on cooler settings, you could have a faulty compressor or low refrigerant levels.
  • An unexplained increase in electricity bills – when there is a problem with your unit it becomes inefficient as it has to work harder, which can increase your power bills regardless of whether it’s still cooling and heating.
  • Leaks or excess moisture – a small amount of water on the outside unit is expected, as it is generally just condensation. However, if you are noticing large amounts of moisture inside the house, there is a problem. Typically it means there is a refrigerant leak, so stop using the unit and schedule a service as soon as you can.
  • Strange smells or noises – air conditioners should be odourless and reasonably quiet. Strange smells could indicate mould inside your ducting, and unusual noises most likely caused by a mechanical problem.