How to Maintain and Care for Your Split System Air Conditioner

At Artarmon Air Conditioning, we believe that with the right care, most homeowners can maintain their split system without needing frequent professional servicing. Modern systems are smart — they’re designed to alert you if something goes wrong. That said, a bit of regular maintenance can go a long way to keep things running smoothly and avoid issues down the track.

1. Clean the Filters

Clogged filters are the most common cause of reduced airflow and poor performance. Open the front cover of the indoor unit, remove the filters, rinse them under warm water, and allow them to dry completely before refitting. This should be done every 1–3 months depending on usage and environment (e.g. pets, dust, or allergies). If you're unsure how to do this, here's a short Daikin video guide on how to clean your split system filters — the process is similar across most brands.

2. Wipe Down the Indoor Unit

Dust can build up on the top and front of the indoor unit. Wipe it down gently with a damp cloth — no need for sprays or harsh cleaners.

3. Spray Glen 20 on the Coil (Optional)

Behind the filters is the indoor coil (the thin metal fins). You can give this area a light spray with Glen 20 or a similar antibacterial spray, then run the unit on cooling mode for 10–15 minutes to help rinse it through. This helps keep odours at bay.

4. Inspect the Fan Barrel

With the system off, shine a torch up through the vents to check the fan barrel. If there’s noticeable dust or grime, this can reduce airflow and may eventually lead to noise or balance issues. If it looks dirty, give us a call — deep cleaning requires removing the casing and should be done by a professional.

5. Check the Outdoor Unit

Important: Only carry out this inspection if it’s safe to do so — for example, if the outdoor unit is at ground level and easily accessible. If the unit is located in a difficult-to-reach area (e.g. on a roof, wall bracket, or narrow side access), it’s best to forgo this step or contact a professional.

Wipe the exterior: Clear dust, cobwebs, and debris from the top and front.

• Inspect the fins: If the metal fins behind the unit are clogged with lint, dirt, or garden matter, this can affect performance. Avoid poking them — just take note and give us a call if they're blocked or damaged.

• Clear the surrounds: Trim back plants and ensure nothing is crowding the unit. It needs good airflow to function properly — at least 300mm clearance is ideal.

6. If Something Goes Wrong: Error Codes & Resets

Most modern split systems will throw up an error code on the indoor unit or controller display if there’s a fault. Occasionally, this can be a software glitch — turning the power off at the switchboard for 10 minutes can reset the unit. If the code comes back after a reset, give us a call and we’ll investigate further.

7. Watch Out for Summer Water Leaks

If you skip professional servicing, the main issue to keep an eye on is water leaking from the indoor unit in cooling mode. This usually happens due to:

• Blocked drain line: Dirt or mould buildup from humid air can clog the drain.

• Poor drain design: Some systems have undersized drain pipes or awkward drain runs that don’t fall properly, especially if installed on the cheap.

• Lack of maintenance: If the filters and coil stay dirty, the system draws in more dust and debris, which ends up in the drain tray.

If you see water leaking or dripping inside during summer, switch the unit off and give us a call.

8. Do You Really Need Professional Maintenance?

In our view — not always. If you're proactive with cleaning, keep the surrounds clear, and the unit’s working fine, there's usually no urgent need for a service. That said, if:

• The unit isn’t cooling/heating properly after cleaning the filters

• You hear unusual noises

• There’s visible rust or corrosion

• Water leaks occur indoors

• You see an error code that doesn’t clear with a reset

• You are unsure of the last service date of the unit

…it’s time to get someone in.

Need Help or Not Sure What You're Looking At?
Give us a call. We’re happy to provide honest advice — and if it’s something that needs attention, we’ll let you know your options without the upsell.