Chemical wash vs chemical overhaul side by side
The difference between a chemical wash and an overhaul is how far the unit is taken apart. The live chemical wash and chemical overhaul pages cover each service in more detail.
| Point | Chemical wash | Chemical overhaul |
|---|---|---|
| Unit dismantled | No, cleaned in place | Yes, the fan coil is taken apart further |
| Parts cleaned | Coil and filters | Coil and filters, plus blower and drain pan |
| Time and labour | Less | More |
| Usually suggested for | Dirty coil, weak airflow | Heavy dirt or mould in the blower |
Treat each row as a point to check, since companies word their lines differently.
What is dismantled in each
In a chemical wash, the technician cleans the coil and filters with chemicals while the unit stays in place.
In a chemical overhaul, the fan coil is taken apart further so the technician can also clean the blower and drain pan. That is why it needs more time and labour.
Companies describe their scope differently, so read what each line says before you compare prices. Questions worth asking:
- Which parts are taken apart, and which are cleaned in place?
- Are the blower and drain pan cleaned, or only the coil and filters?
- Is the rate per unit, and does it change with the size of the unit?
Weighing a general service too? See chemical wash vs general servicing.
Risks to coils and plastics
Chemicals and dismantling should be left to a trained technician. Before the job, ask:
- Which chemicals will be used, and on which parts?
- How will the chemicals be rinsed off after cleaning?
- Who is responsible if a part breaks while the unit is taken apart?
The owner guidance from Daikin Singapore covers the filter: wash it gently with mild soap and lukewarm water, and use no cleaning agents other than mild soap. For servicing and repair, Daikin says owners can engage a Daikin professional through its call centre, before and after the warranty period.
Price by unit size
The table below shows one lowest published rate per company, per unit, for one unit of each size in British thermal units (BTU). Each rate is quoted as printed and linked to its source.
FROM THE HOMEZYPRO DIRECTORY
Published single-unit rates by unit size
Single-unit rates where the company names the unit size or a ceiling cassette. Each cell uses one lowest published rate per company and is left empty when fewer than 3 companies publish one. Figures are advertised rates with conditions, not quotes or a market average.
| Service | 9,000 BTU | 12,000 BTU | 18,000 BTU | 24,000 BTU | Ceiling cassette |
|---|---|---|---|---|---|
| General servicing | No published rates | No published rates | No published rates | No published rates | No published rates |
| Chemical wash | S$80 to S$1206 companies | S$85 to S$1303 companies · median S$100 | S$80 to S$1503 companies · median S$120 | Only 2 companies | Only 1 company |
| Chemical overhaul | S$120 to S$163.508 companies · median S$150 | S$120 to S$15012 companies · median S$150 | S$140 to S$2205 companies · median S$180 | S$170 to S$2806 companies | Only 1 company |
| Gas top-up | No published rates | No published rates | No published rates | No published rates | No published rates |
See the 43 published rates and sources behind these cells
| Company | Cell | Service as listed | Rate | Source |
|---|---|---|---|---|
| Techmen Engineering Pte. Ltd. | Chemical wash, 9,000 BTU | Chemical wash, 9,000 BTU, 1 unit | S$80 per unit | peakcool.sg |
| Airmaxx Aircon Pte Ltd | Chemical wash, 9,000 BTU | Chemical wash 9k-12k BTU, 1 unit | S$85 per unit | airmaxxaircon.com |
| Bencool Services | Chemical wash, 9,000 BTU | Chemical wash, 9000 BTU (1 HP) unit | S$90 per unit | bencoolservices.com.sg |
| Goodcool | Chemical wash, 9,000 BTU | Aircon Chemical Wash 9K-15K BTU | S$92.65 per unit | bestairconservicing.com |
| Easy Cool Engineering Pte Ltd | Chemical wash, 9,000 BTU | FCU chemical wash, non-dismantle, 9k and 12k | S$100 per unit | easycool.sg |
| 338 Aircon | Chemical wash, 9,000 BTU | Chemical wash 9K BTU | S$120 per unit | 338aircon.sg |
| Airmaxx Aircon Pte Ltd | Chemical wash, 12,000 BTU | Chemical wash 9k-12k BTU, 1 unit | S$85 per unit | airmaxxaircon.com |
| Easy Cool Engineering Pte Ltd | Chemical wash, 12,000 BTU | FCU chemical wash, non-dismantle, 9k and 12k | S$100 per unit | easycool.sg |
| 338 Aircon | Chemical wash, 12,000 BTU | Chemical wash 12K BTU | S$130 per unit | 338aircon.sg |
| TJ Aircon Engineering | Chemical wash, 18,000 BTU | Chemical Wash, 1 unit (9,000-18,000 btu) | S$80 per unit | tjaircon.com.sg |
| Easy Cool Engineering Pte Ltd | Chemical wash, 18,000 BTU | FCU chemical wash, non-dismantle, 18k and 24k | S$120 per unit | easycool.sg |
| 338 Aircon | Chemical wash, 18,000 BTU | Chemical wash 18K BTU | S$150 per unit | 338aircon.sg |
| Airvice Chapter | Chemical overhaul, 9,000 BTU | Chemical overhaul, 9K-12K BTU | S$120 per unit | airvicechapter.com |
| Airmaxx Aircon Pte Ltd | Chemical overhaul, 9,000 BTU | Chemical overhaul, 9k to 12k BTU | S$130 per unit | airmaxxaircon.com |
| Aera Pte Ltd | Chemical overhaul, 9,000 BTU | Wall Mounted Chemical Overhaul 9k-12k BTU | S$150 per unit | aera.sg |
| Cool Aircon | Chemical overhaul, 9,000 BTU | Chemical overhaul, wall-mounted 9k/12k BTU | S$150 per unit | coolaircon.sg |
| EC Aircon Services Pte Ltd | Chemical overhaul, 9,000 BTU | Chemical overhaul, 9K-12K BTU | S$150 per unit | ecaircon.com |
| Heng Aircon Pte Ltd | Chemical overhaul, 9,000 BTU | Chemical overhaul 9k and 12k BTU | S$150 per unit | hengaircon.com |
| 338 Aircon | Chemical overhaul, 9,000 BTU | Chemical overhaul 9K BTU | S$160 per unit | 338aircon.sg |
| Goodcool | Chemical overhaul, 9,000 BTU | Aircon Chemical Overhaul 9K-15K BTU | S$163.50 per unit | bestairconservicing.com |
| Airvice Chapter | Chemical overhaul, 12,000 BTU | Chemical overhaul, 9K-12K BTU | S$120 per unit | airvicechapter.com |
| Airmaxx Aircon Pte Ltd | Chemical overhaul, 12,000 BTU | Chemical overhaul, 9k to 12k BTU | S$130 per unit | airmaxxaircon.com |
| City Cooling Pte Ltd | Chemical overhaul, 12,000 BTU | Chemical overhaul FCU, 9/12K BTU, 1 unit | S$130 per unit | citycoolingengr.com.sg |
| Non-Stop Cooling Aircon Service Singapore | Chemical overhaul, 12,000 BTU | Chemical Overhaul (9000 & 12000 BTU) | S$130 per unit | nonstopaircon.com |
| A-Max Aircon | Chemical overhaul, 12,000 BTU | Chemical overhaul 9000-12000 BTU | S$150 per unit | amaxaircon.com |
| Aera Pte Ltd | Chemical overhaul, 12,000 BTU | Wall Mounted Chemical Overhaul 9k-12k BTU | S$150 per unit | aera.sg |
| Airconman Sg Pte Ltd | Chemical overhaul, 12,000 BTU | Chemical overhaul, 1 fan-coil unit (9000 & 12000 BTU) | S$150 per job, 1 fan-coil unit | airconman.sg |
| Cool Aircon | Chemical overhaul, 12,000 BTU | Chemical overhaul, wall-mounted 9k/12k BTU | S$150 per unit | coolaircon.sg |
| EC Aircon Services Pte Ltd | Chemical overhaul, 12,000 BTU | Chemical overhaul, 9K-12K BTU | S$150 per unit | ecaircon.com |
| Heng Aircon Pte Ltd | Chemical overhaul, 12,000 BTU | Chemical overhaul 9k and 12k BTU | S$150 per unit | hengaircon.com |
| Thetop Aircon Service | Chemical overhaul, 12,000 BTU | Chemical overhaul 9-12k, 1 unit | S$150 per unit | thetop.com.sg |
| TJ Aircon Engineering | Chemical overhaul, 12,000 BTU | Chemical Overhaul, 1 unit (9,000-12,000 btu) | S$150 per unit | tjaircon.com.sg |
| Airvice Chapter | Chemical overhaul, 18,000 BTU | Chemical overhaul, 18K BTU | S$140 per unit | airvicechapter.com |
| Airmaxx Aircon Pte Ltd | Chemical overhaul, 18,000 BTU | Chemical overhaul, 18k BTU | S$160 per unit | airmaxxaircon.com |
| Aera Pte Ltd | Chemical overhaul, 18,000 BTU | Wall Mounted Chemical Overhaul 18k BTU | S$180 per unit | aera.sg |
| Cool Aircon | Chemical overhaul, 18,000 BTU | Chemical overhaul, wall-mounted 18,000 BTU | S$180 per unit | coolaircon.sg |
| EC Aircon Services Pte Ltd | Chemical overhaul, 18,000 BTU | Chemical overhaul, 18K-24K BTU | S$220 per unit | ecaircon.com |
| Airvice Chapter | Chemical overhaul, 24,000 BTU | Chemical overhaul, 24K BTU | S$170 per unit | airvicechapter.com |
| Airmaxx Aircon Pte Ltd | Chemical overhaul, 24,000 BTU | Chemical overhaul, 24k BTU | S$200 per unit | airmaxxaircon.com |
| Aera Pte Ltd | Chemical overhaul, 24,000 BTU | Wall Mounted Chemical Overhaul 24k BTU | S$210 per unit | aera.sg |
| EC Aircon Services Pte Ltd | Chemical overhaul, 24,000 BTU | Chemical overhaul, 18K-24K BTU | S$220 per unit | ecaircon.com |
| Cool Aircon | Chemical overhaul, 24,000 BTU | Chemical overhaul, wall-mounted 24,000 BTU | S$240 per unit | coolaircon.sg |
| 338 Aircon | Chemical overhaul, 24,000 BTU | Chemical overhaul 24K BTU | S$280 per unit | 338aircon.sg |
For a chemical wash, 6 companies publish a rate for one 9,000 BTU unit; their lowest published rates run from S$80 to S$120 per unit. For 12,000 BTU, 3 companies publish a rate, from S$85 to S$130 per unit. For 18,000 BTU, 3 companies publish a rate, from S$80 to S$150 per unit.
For a chemical overhaul, 8 companies publish a rate for one 9,000 BTU unit, from S$120 to S$163.50 per unit. For 12,000 BTU, 12 companies publish a rate, from S$120 to S$150 per unit. For 18,000 BTU, 5 companies publish a rate, from S$140 to S$220 per unit. For 24,000 BTU, 6 companies publish a rate, from S$170 to S$280 per unit.
These are published rates as printed, not quotes. The table has no ceiling cassette cell. When pricing chemical overhaul vs chemical wash, compare cells of the same size. The aircon servicing cost estimator shows the same rates for one size at a time.
See also the guides on chemical wash cost by BTU and chemical overhaul cost.
How often
None of the official sources here gives an interval for either service, so ask the technician what they found.
The National Environment Agency (NEA) advises checking the aircon filter once a month and cleaning or replacing it when necessary. It also advises servicing aircon units regularly and getting them inspected annually.
In an HDB flat, HDB advises regular checks: brackets on concrete or brick walls only, not timber frames; stainless steel brackets free of corrosion and rust; no leaking; and condensate piping running into the flat to a floor trap. Ask your aircon serviceman whether a corroded or rusty unit needs replacing. HDB warns that an improperly installed or maintained aircon can fall and cause serious injury or death to people below.
For an old unit, NEA suggests weighing life cycle cost: purchase price plus annual energy cost multiplied by lifespan in years. See whether to repair or replace an old aircon.
NEXT STEP
See aircon servicing companies with their published prices, the areas they say they cover and their sources.
Compare aircon servicingWhich one should you choose?
Use these as questions to ask the company, not fixed rules.
- Chemical wash. Is the unit dirty but not heavily mouldy, and does the company say a wash will do?
- Chemical overhaul. Did the technician find heavy dirt or mould in the blower or drain pan?
- Either service. Can you get photos and a written scope listing the parts cleaned?
To shortlist, compare aircon companies and check aircon servicing prices for other lines.
Questions
Is a chemical overhaul worth the extra cost?
It depends on what is inside the unit. An overhaul also cleans the blower and drain pan, and is usually suggested for heavy dirt or mould in the blower. If the technician finds only a dirty coil, ask whether a wash would do, and get photos and a written scope first.
How often should I do a chemical wash?
None of the official sources here gives an interval for a chemical wash. The NEA advises checking the filter once a month, servicing aircon units regularly and getting them inspected annually. Ask your technician whether the coil needs a wash, based on what they see during a service.
Can a chemical wash remove mould?
A wash cleans the coil and filters with the unit mostly in place. An overhaul goes further and reaches the blower, where mould can build up, and the drain pan. If the technician finds mould in those parts, ask whether an overhaul is needed. The guide to mould in an aircon has more on this.
Does a chemical overhaul include topping up the gas?
None of the rates on this page includes gas. Ask the company whether gas is checked or topped up during an overhaul, and whether that is part of the price or charged separately. Get the answer in the written scope so you can compare companies on the same basis.
How long does each service take?
No source here gives a time for either service. An overhaul takes longer than a wash because more of the unit is dismantled. Ask the company how long the job will take for your units when you book, and whether the time changes with unit size.
Can I do a chemical wash myself?
Chemical cleaning is a job for a trained technician. Daikin Singapore says owners can wash the filter every two weeks with mild soap and lukewarm water, rinse it, let it dry completely and re-install it, and should not use cleaning agents other than mild soap. For a wash or overhaul, book a technician.
Prices come only from the sourced company rates in the HomezyPro directory, shown with each company and its source.
Practical guidance for planning a home job in Singapore. Company prices come from the HomezyPro directory, each linked to its source; rules and safety points link to the agency or manufacturer that sets them. This is not a site inspection, a quote or professional advice for your home.
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