Updated 2026-10-11 · AirconList
Short answer: A chemical wash partially dismantles the indoor unit to clean the coil, blower and drain tray, every 6 to 12 months, for about S$80 to S$120 a unit. A chemical overhaul fully dismantles the indoor and outdoor units, cleans each part and checks worn parts, every 3 to 5 years, for about S$150 to S$250 a unit (S$350 for ceiling units at one provider).
The difference in one table
From Helpling’s February 2026 guide (Helpling):
| Chemical wash | Chemical overhaul | |
|---|---|---|
| What happens | Partial disassembly of the indoor unit to reach the coils, blower wheel and drainage | Complete dismantling of indoor and outdoor units; each component cleaned separately |
| Parts | Not replaced | Worn parts such as capacitors, bearings and gaskets inspected and replaced |
| How often | Every 6 to 12 months | Every 3 to 5 years |
| Price per unit | S$80 to S$120 | S$150 to S$250 |
Helpling’s own price list is more specific: wash S$80 (9k to 18k BTU) or S$100 (24k BTU); overhaul S$160, S$180 and S$350 for a ceiling unit (Helpling price list).
Which one you need
- Serviced regularly, cooling fine, a little smell: a chemical wash.
- Not serviced for over a year, heavy dirt, smells or leaks that keep coming back: an overhaul.
- Not sure: ask the technician to open the front panel and show you the coil before choosing.
Compare companies for chemical washes or estimate the cost.
Want an aircon company to quote?
Free. Tell us what your aircon needs; a company calls you back with a price.
Request received.
An aircon company will call you on the number you gave. If water is dripping near a socket, switch that aircon off until it is checked.
More questions
Is an overhaul always better?
No. For a regularly serviced unit, a wash is usually enough. An overhaul suits units with heavy build-up or that have gone more than a year without servicing.
Does a chemical wash include a gas top-up?
Not as standard. Ask the company: some packages include a check or a partial top-up.