Cleaning Your Split System Air Conditioner

checking pressure after cleaning air conditioner

Air conditioning may not be on your mind right now, but the cooler months are a great time to ensure your split system is clean, well-maintained, and ready for next summer. 

Regular cleaning and maintenance keep your split system running efficiently to keep energy bills in line and support a healthier indoor environment.

In this guide to cleaning your split system air conditioner, I’ll cover why you should clean your split system, how to clean split system air con, and an example cleaning schedule.   

How to Clean Your Split System Air-conditioner

 Key Takeaways:

  • Cleaning split system aircon units is important for ensuring efficiency and effectiveness, and maximising the unit’s lifespan
  • Split system cleaning should happen anytime the unit is dirty and on a monthly, bi-annual, and annual basis 
  • Always check and follow the manufacturer’s cleaning and maintenance instructions and schedule an annual professional servicing
  • Split system AC cleaning should involve regularly wiping down the exterior of the unit, keeping filters and coils clean, and watching for common AC issues
Air con expert removing an aircon unit from the wall
air con removal service

Why Should You Clean Your Split System 

A split system air conditioner with blockages, dust build-up, or dirty filters will struggle to cool the air. This forces the system to work harder than it needs to and can lead to unexpectedly high energy bills. Dirty filters can also lower indoor air quality. This is especially concerning for homes with young children, elderly occupants, or individuals with asthma or respiratory issues. 

Benefits of regular split system cleaning include: 

  • Prevent common AC problems
  • Ensure efficiency
  • Promote a healthier indoor environment 
  • Help maximise the unit’s lifespan
  • Reduce energy consumption and power bills


How to Clean Split System Aircon

The filters and coils are the big focus regarding cleaning split system aircon units. Filters help clear dust and particles out of the air, ensuring efficiency and promoting healthier indoor air. If the filters are dirty or clogged, the AC unit is forced to work harder and indoor air quality may decrease. Coils that are clogged with dust or dirt will struggle to maintain efficient airflow. 

Before you start cleaning, make sure you have the proper supplies on hand. We recommend a vacuum with a soft-bristle brush attachment, a micro-fibre cloth, and a mild detergent solution. 

Here are the general steps to split system cleaning: 

  • Read the user’s manual prior to cleaning the unit and follow the manufacturer’s cleaning instructions
  • Always make sure the unit is turned off and unplugged before cleaning 
  • Wipe down all exterior surfaces with a slightly damp cloth
  • Remove the service panel and make sure there is no dust, dirt, or debris in the unit and check for damage
  • Wipe away any dust from fan blades
  • Remove the filter and clean it according to the manufacturer’s instructions (usually, you can simply use a microfibre cloth to dust off the filter and a cleaner made for split system cleaning)
  • If the filter is still clogged after cleaning, or if it is due to be changed, replace the filter
  • Always let the filter or coils dry completely before placing them back in the unit
  • Check the unit’s condenser to make sure it is clear of debris, dirt, and dust and use a coil cleaner to clean it
  • If needed, use a brush to sweep away debris from the condenser’s fin
  • Replace the service cover


checking pressure after cleaning air conditioner

When to Clean Your Split System

Here is a general schedule for cleaning split system air conditioners: 


  • Monthly Split System Cleaning

Every 30 days, clean the filters and check them over. Generally, we recommend replacing filters every 3 months. Homes with kids, pets, or allergy sufferers may need filters cleaned and replaced more often. Give the surface of the unit a quick wipe down every month, or when you notice visible dirt. 


  • Bi-Annual Split System Cleaning

Twice a year, we recommend wiping down all vents, ducts, or surfaces of both the indoor and outdoor unit with a soft, slightly damp cloth. Only wipe down areas you can easily reach. This is also a great time to make sure no debris building up inside the unit. Take the service panel off and inspect the vents, coils, and surfaces for debris, blockages, or build up. 


  • Annual Split System Cleaning

Along with regular cleaning throughout the year, we recommend scheduling an annual professional inspection. A certified AC technician can check the coolant levels, confirm there are no leaks, ensure the unit and coils are thoroughly cleaned, and ensure the unit is running efficiently. 

 Learn more about regular split system maintenance in my guide here: The Best Tips for Maintaining Your Split System Air Conditioner.


Signs You Need Split System AC Cleaning

If you notice these signs, it may indicate you need split system cleaning: 

  • Odd Noises — If you notice unusual humming sounds or odd noises coming from your split system AC, check to see if it needs to be cleaned. A unit that is louder than usual when running or making knocking sounds may be clogged with dirt or in need of professional servicing.
  • Lack of Cold Air — Lack of cool air coming out of your AC indicates the need for maintenance. This may be as simple as changing the filter and a thorough wipe down or further maintenance may be required. 
  • Musty or Bad Smells — Burning, musty, or odd smells coming from your split system indicate the need for cleaning and maintenance. 
  • Higher Energy Bills — If you notice an unexplained spike in your energy bills, make sure your split system isn’t dirty. A dirty AC unit will lose efficiency and work harder than needed, leading to higher energy bills.
  • Visual Dust or Dirt — Anytime you notice dust or dirt accumulating on the exterior surface of the unit, give it a quick wipedown.

Learn More: How to Tell Your Air Conditioner Needs Servicing


Tips and Tricks on How to Clean Split System Aircon 

Here are some of our favourite tricks for split system AC cleaning:

  • Check the Manual

Always reference the manual that came with your split system air conditioner. Follow the recommendations for cleaning and maintenance.

  • Use the Seasons 

Before summer or before the cooler months set in, use it as a reminder to give your split system a good cleaning. 

  • Remove Obstructions or Blockages

Make sure there are no books, dressers, furniture, clothes, blankets, drapes, or other items blocking the air conditioner vents on the indoor unit. Outside, ensure the unit is free of any obstructions, such as plants, trees, branches, or leaves. 

  • Run Just the Fan

Once a month, we recommend turning on the air conditioner’s fan-only mode for about 30 minutes to an hour. This will help any lingering moisture inside the unit evaporate.

  • Avoid Compressed Air

We do not recommend using compressed air to clean dust out of the unit. If you notice dust on the coils or fan blades, use a slightly damp cloth to wipe them down instead. 

  • Be on the Lookout for Common AC Issues

Always be on the lookout for leaks, icy coils, poor airflow, or other issues. These may be signs of a clogged filter, damage, or blockage in the unit.

  • Know When to Enlist a Professional

If you’ve given your split system a good cleaning and changed the filter and it is still experiencing issues with cooling, odd noises, or musty smells, contact a professional AC technician. The technician will ensure the components are working properly, pinpoint any issues, and ensure your unit is running efficiently again. 


Perth’s Air Conditioner Experts

Has it been years since your split system was inspected? Or do you need help choosing the right split system for your home and energy needs. Get in touch with our experts here at Air Cond Installs for your free quote or with questions. We supply and install split system air con units to Perth’s northern suburbs, offering trusted service, fair pricing, and the best brands in the industry. 

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