How to Clean a Split System Air Conditioner Filter
Cleaning your split system air conditioner filter is one of the most important pieces of maintenance you can do. A dirty filter reduces cooling efficiency, increases electricity bills and can cause the unit to freeze or leak. The good news: it takes about 10 minutes and costs nothing.
How Often Should You Clean the Filter?
As a general guide:
- Every 4 weeks during heavy use (summer and winter peaks)
- Every 2 months during lighter use periods
- Immediately if you notice reduced airflow, unusual smells or higher electricity bills
Homes with pets, smokers or high dust levels should clean filters more frequently.
What You'll Need
- A step stool or ladder (depending on your unit's height)
- Warm water and mild dish soap
- A soft brush or cloth
- A clean dry towel
Step-by-Step: How to Clean Your Split System Filter
Step 1: Turn Off the Unit
Switch the air conditioner off at the remote and at the wall switch. Never clean the filter with the unit running.
Step 2: Open the Front Panel
Most split system indoor units have a front panel that lifts or swings open. Gently lift it upward — it typically hinges from the top. Some models have small tabs on the sides you need to press first. Refer to your owner's manual if unsure.
Step 3: Remove the Filters
The filters are typically mesh panels that slide or unclip from inside the front panel. They are usually grey or white mesh and may have a light frame. Slide them down and out carefully. Most units have two filters, one on each side.
Step 4: Vacuum Off Loose Dust
Use a vacuum cleaner with a brush attachment to remove loose dust from the filter. This prevents dust from spreading when you wet the filter.
Step 5: Wash Under Running Water
Rinse the filter under warm (not hot) running water. Run the water from the clean side through to the dirty side to push debris out the way it came in. For stubborn grime, use a soft brush with mild dish soap. Never scrub the mesh aggressively — you can distort the mesh material.
Step 6: Allow to Dry Completely
Shake off excess water and lay the filters flat on a clean dry towel. Let them air-dry completely in a shaded spot — never in direct sunlight, which can warp plastic components. Never reinstall a wet filter. A wet filter can promote mould growth inside the unit.
Step 7: Reinstall the Filters
Once fully dry, slide the filters back into their slots. Close the front panel until it clicks. Turn the unit back on and check that airflow is normal.
Beyond the Filter: What Else Should You Clean?
While the filter is out, inspect the evaporator coil (the finned metal coil behind the filter). If you see visible dust or dark deposits on it, it may need a professional coil clean. This is typically done as part of an annual service. Do not spray water directly onto the coil, electrical components or the front panel display.
When to Call a Professional
If cleaning the filter doesn't improve performance, or if you notice unusual smells (musty, burning), ice on the unit, or water dripping inside, contact a licensed air conditioning technician.
Need a New Air Conditioner?
If your air conditioner is old, inefficient or frequently causing problems, it may be time to upgrade. Oceania Appliances stocks Daikin, Mitsubishi Electric and Fujitsu split systems. Visit our Wetherill Park showroom or contact us at support@oceaniaappliances.com.au.