What You Can Safely Do Yourself
Cleaning the filters is the one aircon job you can and should do at home between visits. If you want to know how to clean aircon filter yourself, it takes about five minutes a unit and needs only a tap, mild soap and a soft brush.
Here is the simple routine:
- Switch the unit off at the remote and, ideally, at the wall.
- Open the front cover and slide out the filters. Most wall units have one or two mesh filters.
- Rinse under a tap with lukewarm water and mild soap. Brush gently if needed.
- Dry fully in the shade, not in direct sun, so they do not warp.
- Refit and close the cover.
Skip the hot water. A January 2026 DIY guide from Homejourney warns that it can warp or shrink some filter materials. Cleaning Assistant, a Singapore cleaning company, adds that bleach and strong degreasers can weaken the mesh.
How Often to Clean Them
Do this every two to four weeks for daily-use units. NEA’s household energy tips recommend inspecting filters monthly, and Daikin’s maintenance guidance suggests cleaning them every two weeks.
If you have 2 to 4 units in your flat, don’t do them all in one go. Rinse one room’s filters each weekend and the whole flat stays on a steady cycle. It is the single best habit for keeping cooling steady, and it pairs well with professional aircon servicing on the usual schedule.
What DIY Cannot Reach
Behind the filter sits the part of the unit you should not clean yourself. Three components need a technician:
- The evaporator coil, the cold fins where dust and mould stick hardest
- The blower wheel, the long spinning drum that throws the air out
- The drain pan and drain line, where sludge and mould cause leaks and smells
These need the right tools, cleaning solution and know-how. A surface rinse does nothing for them, and this is exactly what a professional service, or a deeper chemical wash, is for.
A musty smell is usually the giveaway. Helpling, a Singapore home services platform, notes that it often points to mould on the blower wheel or drain pan.
DIY vs Professional at a Glance
| Part of the unit | What you do at home | What a technician does |
|---|---|---|
| Filters | Rinse every 2 to 4 weeks | Check and clean at each visit |
| Evaporator coil | Leave alone | Clean with the right solution and catchment |
| Blower wheel | Leave alone | Wash to remove mould and grime |
| Drain pan and line | Leave alone | Flush out sludge and test the flow |
Chemical wash prices vary by provider and scope. A 2026 price guide from SJR Aircon puts a standard wash at S$100 to S$180 per split unit, while Helpling lists S$80 to S$100 for a wall-mounted unit.
Why Spraying the Coil Yourself Is Risky
Yes, it is risky, because the coil sits right beside the electronics and the drain. Shop-bought “aircon cleaner” sprays are tempting, but spraying the coil or the electrics yourself can cause real trouble:
- Cleaner that is not rinsed out properly can corrode fins or clog the drain
- Overspray onto the PCB or wiring can short the board
- Without a catchment bag, the dirty run-off goes down your wall
Sky Blue Aircon, a Singapore servicing company, points out that the control PCB and the temperature sensors sit right next to the evaporator coil. Silverback Aircon adds that many of these sprays are acidic and can damage the coils if left on too long.
The drain is the other trap. A blocked drain pipe is the most common cause of leaks in Singapore HDB flats, and extra liquid from a DIY spray makes a struggling drain worse. Silverback also warns that a badly cleared drain can ruin false ceilings and wooden flooring, and cause disputes with the neighbours below.
What looks like a saving can turn into a repair bill. If the cooling is weak or there is a smell, it is safer to book a service than to spray.
The Honest Verdict
Clean the filters yourself, often. Leave the coil, blower and drain to a technician. Regular filter cleaning genuinely extends the time between professional services, but it does not replace them.
At Cool Earth Aircon, we’ve been servicing Singapore aircons since 2007. This split is the advice we give every customer around Marine Terrace, Marine Crescent and Marine Drive.
Read how often to service to set the right interval for your home, then keep those filters rinsed in between. If you’ve already cleaned the filters and the cooling is still weak, or a smell keeps coming back, book a service with us and we’ll check the coil, blower and drain properly.