What's in a typical kit
Most DIY kits are a can of foaming coil cleaner, sometimes with a plastic catch bag or cover to stop water running down the wall. Some come with a brush or a spray bottle. They're designed for the front of the evaporator coil on a wall-mounted split system.
What a DIY kit does well
- Freshens up the front face of the coil between professional cleans
- Good for a unit that's cleaned regularly and only lightly dusty
- Cheap, and you can do it on your own time
What it can't reach
The parts that cause the smell and the black specks are behind and below the front of the coil:
- The barrel fan. This long cylinder of blades is where most of the mould ends up, and you can't clean it properly without taking the cover off and getting water through it.
- The back of the coil and the drain tray. Foam sprayed on the front pushes some of the dirt deeper in and down into the tray.
- The drain line. If the foam and grime aren't rinsed through, they can block the drain — and a blocked drain is what makes splits drip down the wall.
- The outdoor unit. Kits are for the indoor coil only.
Be careful with DIY
Always switch the unit off at the isolator before you touch it, keep spray and water away from the electronics behind the side panel, and only use products made for air conditioner coils.
Working on a ladder over furniture with a can of foam is also how a lot of walls and carpets get stained. Put down drop sheets and use a catch bag.
When to call a professional
- It still smells after you've washed the filters
- There are black specks on the louvres or the wall
- Water is dripping from the indoor unit
- It's never been professionally cleaned, or not for a few years
- Someone in the house has asthma or allergies
Our split system clean is $210 with the outdoor unit, drain flush and a slow-release drain tablet included, or $290 for a full strip-down. Keep the kit for top-ups in between, and wash the filters yourself every month or two. Not sure how often? Read how often to clean your aircon in Perth.