The Short Answer
Clean the aircon filter yourself every 2 to 4 weeks. Leave everything behind it to a technician every 3 to 4 months. It is what we tell every customer who books aircon servicing in Jurong with us, and Brian has given the same advice since he started Cool Earth Aircon in 2007.
The two-week rhythm comes from manufacturer guidance. Daikin recommends cleaning filters every two weeks, while NEA’s household energy tips suggest checking them monthly and cleaning when needed. Each wall unit takes about 15 minutes, so a 3-unit HDB flat is done in under an hour.
DIY filter cleaning is safe, quick and free. But the filter is only the first line of defence.
The parts that cause smells, leaks and weak cooling sit behind it. Those need tools, a wash bag and a trained hand. When those parts are coated, a chemical wash is the job that brings the unit back.
How to Clean Aircon Filters Safely
Switch off, lift the panel, slide out the filters, rinse, dry in the shade and refit. Six steps, about 15 minutes per unit, and no tools.
- Switch off the aircon with the remote and at the power switch.
- Lift the front panel until it clicks open. Most wall-mounted units hinge upwards.
- Slide out the mesh filters. They usually pull down and out. Note how they sit.
- Rinse with water from the back of the filter, so dust is pushed out the way it came in. Lukewarm water works well. Use a soft brush for stubborn spots.
- Dry in the shade. Direct sun can warp the plastic frame. Make sure the filter is fully dry.
- Refit and close the panel, then switch the unit back on.
Do not run the unit without filters
Even for a short while. Dust goes straight onto the coil, which is far harder to clean than the filter.
Here is a habit that helps in a flat with 3 or 4 units. Wash them all on the same day and set a phone reminder. Units in bedrooms used every night clog faster than a living room unit, so check those first.
Some models have special filters, such as a coated or deodorising one. Follow your model’s manual for those, since the method and timing can differ.
What DIY Cannot Reach
Behind the filter, the important parts are out of reach without taking the unit apart. Here is what sits back there and why each part matters.
| Part | Can you clean it at home? | Why it matters |
|---|---|---|
| Filter | Yes, every 2 to 4 weeks | Keeps airflow up and dust off the coil |
| Evaporator coil | No | Coated fins cause weak cooling and higher bills |
| Blower wheel | No | Mould here causes smells and black specks |
| Drain pan | No | Sludge here overflows as leaks |
| Drain line | No | Needs a flush or pump to clear |
| Outdoor unit | No | Electrical and refrigerant parts on the ledge |
Coil cleaner sprays sold online promise a DIY deep clean. We do not recommend them. The spray drips onto the PCB control board, it does not rinse out the dirt it loosens, and the run-off often ends up in the drain pan as fresh sludge.
A blocked drain is more than a wet floor. NEA’s guidance on aircon drip trays points out that a choked drainage point leaves water ponding, and Aedes mosquitoes breed in clean, still water. Never place a tray under a leaking unit as a quick fix. Call us to clear the line.
Signs DIY Is No Longer Enough
Book a technician if you notice any of these, even with clean filters:
- The room still takes a long time to cool
- A musty or sour smell when the unit starts
- Black specks on the louvres or the wall below
- Water dripping from the unit
- It has been more than 4 months since the last servicing
Most of these point to a dirty coil or blower wheel. A general service handles light cases. Heavier build-up needs a chemical wash.
Cost is usually the worry, so here are the numbers. Singapore price guides for 2026 put a chemical wash at roughly $80 to $150 per unit, with Coogle quoting that range. Helpling lists wall-mounted units at $80 to $100.
Waiting costs more. A 2026 guide from NewCool says a well-maintained aircon often saves 5 to 15% on electricity, so a dirty coil quietly adds to your monthly bill.
Putting It Together
Think of filter washing as brushing your teeth and servicing as the dentist. One does not replace the other. Washing filters between visits keeps cooling steady and makes each servicing visit quicker.
If you clean the aircon filter yourself on a regular schedule, you will catch most small problems early. For the right gap between visits, read our guide on how often to service your aircon.
Living in Jurong West or Jurong East and spotting a smell, a drip or slow cooling? Book a servicing visit and we will check every unit in your flat in one go.
