Does your aircon smell sour even after a wash? Or are you seeing black specks on the pillow?
That usually means the dirt is sitting where a spray can’t reach. A chemical overhaul is the fix, and it’s what we do in a lot of Jurong West and Jurong East flats.
Aircon Servicing Jurong is the Jurong team of Cool Earth Aircon, which Brian started in 2007. Here’s how an overhaul works, what it costs and when you need one.
What is an aircon chemical overhaul?
A chemical overhaul is the deepest clean we do on an indoor unit. We take the fan coil unit apart on the wall. The front housing, drain pan, blower wheel and fan motor all come out.
We clean each part one by one and wash the evaporator coil in place. Then we apply an anti-bacterial rinse before everything goes back together. We finish with a reassembly test run and an airflow check.
It takes longer than a wash too. Helpling, a Singapore home services platform, puts an overhaul at roughly 3 to 5 hours, against 1 to 2 hours for a wash.
It costs S$130 to S$180 per unit, with a fixed quote before we open the unit.
Why a wash is not always enough
A chemical wash cleans the coil and blower with the unit still assembled. That works well for weak cooling and mild smells. But when a unit has gone years without a deep clean, the dirt changes.
Black mould grows thick on the blower blades. The drain pan fills with jelly sludge, a slimy mix of dust, mould and bacteria. Spraying solution over that doesn’t remove it. The parts have to come out.
Here’s a quick way to tell which one your unit needs:
| Chemical wash | Chemical overhaul | |
|---|---|---|
| Indoor unit | Stays assembled on the wall | Dismantled, parts cleaned one by one |
| Best for | Weak cooling, mild smell, yearly upkeep | Heavy mould, sludge, strong smell, leaks |
| Typical time | 1 to 2 hours | 3 to 5 hours |
Coogle, another Singapore aircon company, suggests an overhaul for units that haven’t had a deep clean in 2 years or more. It also suggests one when a wash hasn’t solved the problem. That matches what we see on the ground.
This is common in older flats in Taman Jurong, Boon Lay and the resale flat blocks around Jurong West Central. Those units have run every day for a decade or more, in Singapore’s humid climate. Mould loves it.
Common problems an overhaul solves
Strong sour smell
A sour, vinegar-like smell usually means bacteria in the drain pan and on the blower. A musty smell is more often mould on the coil. Both are common in Singapore’s humidity.
Removing and scrubbing the pan and blower is the fix.
Black bits blowing out
When mould on the blower dries and flakes, the fan throws it into the room. You may see black specks on the bed, pillow or wall below the unit.
If you spot them, here’s what to do:
- Stop using that unit for now, so it doesn’t spread more.
- Take a photo of the specks and the blower, if you can see it.
- Book an overhaul, because wiping the surface won’t stop the source.
Water leaking from a dirty unit
Sludge blocks the drain outlet, so the pan overflows. Cleaning the pan properly, then flushing the line, stops the leak at its source.
If water still drips after that, the problem may sit in the pipe itself. We’ll tell you straight once we’ve checked.
Severe loss of cooling
A heavily fouled coil and blower move far less air. After an overhaul, most units cool noticeably faster.
On older R410A units, we also check that the cooling problem isn’t a refrigerant issue before you pay for cleaning. A gas top-up is a different job. HomeJourney, a Singapore home services site, quotes S$80 to S$150 for R410A in 2026, and it won’t fix a dirty blower.
What affects the overhaul price?
The range is S$130 to S$180 per unit. For comparison, aircons.sg’s 2026 price guide puts chemical overhauls across Singapore at roughly S$120 to S$250 per unit.
Three things push your price up or down:
- Unit size: larger units sit towards the top of our range.
- Ease of dismantling: tight installations take more time.
- Build-up: very heavy mould and sludge mean more scrubbing.
We confirm the exact price before we start. If a wash will do the job, we tell you and charge the wash price instead.
Got 2 to 4 units at home? Tell us how each one smells and cools. Often only the worst unit needs an overhaul, and the others do fine with a wash.
Keeping it clean afterwards
An overhaul resets the unit. To keep it that way, book general aircon servicing every 3 to 4 months and clean the filters yourself in between. Daikin Singapore recommends professional servicing every three months for daily use, so that’s a sensible rhythm for a bedroom unit.
Our guide to cleaning aircon filters yourself vs booking a technician shows what you can safely do at home. If leaks continue after an overhaul, the cause may be the pipe or drain line, which our aircon water leak repair covers.
Ready to get your aircon chemical overhaul done? Book with us, and we’ll give you a fixed quote before we open a single unit.
