Search for a cheap aircon chemical wash in Singapore and you will find prices all over the place. Some are low enough that you start to wonder how anyone makes money at them. The honest answer is usually that some of the job has been left out. You rarely see it on the day, because a unit that has just been sprayed and wiped looks clean from the outside. You see it three or four weeks later, when the smell comes back.
This post is not here to tell you never to book a cheap wash. It is here to show what a chemical wash is supposed to include, which steps a low price usually drops, and what to ask before you book, so you can compare quotes that are actually quoting the same job. All the figures are from our published price list.
What a chemical wash is supposed to include
A general service is routine upkeep: the filters, a wipe over the coil and a flush of the drain. It keeps a clean unit clean. A chemical wash exists for the point after that, when mould and biofilm have built up inside the evaporator coil and a wipe cannot reach them any more. That is why the steps matter. A "wash" that stops at the surface is just an expensive general service.
This is what goes into every chemical wash we do, step by step:
- The 9-point pre-check. It confirms a wash is actually what the unit needs, rather than a simpler service or a gas problem.
- Power isolated and the fan coil cover removed.
- Coil-safe solution worked into the evaporator coil and given time to break down the mould, biofilm and grime.
- A full pressure rinse to carry the loosened deposits away.
- The drain tray and pipe flushed, treated and vacuumed clear so water runs out freely again.
- An anti-bacterial finish to slow regrowth.
- Reassembly, then the unit run and the cooling checked before the technician leaves.
Reckon on 60 to 90 minutes per indoor unit, with the pre-check and the final test included in that time. Keep that list in front of you when you compare quotes. Each cheap quote is usually missing one or more items from it.
Where a cheap wash usually cuts corners
We don't know how every other company works, and some low-priced operators do good work. But when a price is well below what a full job costs, it tends to get there in one of a handful of ways, and each one shows up later as a problem you pay for.
1. The pre-check is skipped
Without a check first, you pay for a wash whether or not a wash will fix what is wrong. If the real cause of weak cooling is low refrigerant or a failing part, the unit comes out cleaner but no colder, and you have paid for the wrong job. We have a separate post on what a chemical wash cannot fix. It is worth reading before you pay for any cleaning, cheap or not.
2. Harsh or generic chemicals
Coil-safe cleaning solutions cost more than generic ones. The cheaper, harsher chemicals attack the aluminium fins on the coil. You won't notice that on the day. It shows up later, as corroded fins on a coil that costs far more to replace than the wash saved.
3. A short rinse
Rinsing properly takes time, and time is where a low price gets made up. A short rinse leaves residue on the coil, and that residue gives the next round of growth something to start on. The unit looks fine when the technician leaves and fouls faster afterwards.
4. The drain is not treated
This is the most common cut, and the one people notice first. The musty smell is mould and bacteria in the coil and in the drain. If only the coil gets cleaned, the drain tray and pipe re-seed it, and the smell is back within a few weeks. If your "washed" aircon smells again within a month, an untreated drain is the first thing to suspect. Drains also block. A tray full of slime is also how a unit that was dry starts dripping.
5. No test before leaving, no written warranty
A technician who reassembles the unit and leaves without running it has not confirmed anything. And if the only warranty is a verbal "call us if there's a problem", a warranty claim quickly turns into an argument. Every wash we do carries a 90-day workmanship warranty.
The "from" price trap
This one catches people out even with honest companies, including us. Headline prices are usually quoted "from", and the "from" figure is the rate for the largest booking, not the price for your unit.
Our own chemical wash page says from $100 per unit. That rate starts at the fifth unit. The full published table is:
- 1 unit: $135
- 2 units: $245 ($122.50 per unit)
- 3 units: $345 ($115 per unit)
- 4 units: $425 ($106.25 per unit)
- 5 units or more: $100 per unit
So if you have one unit that smells, the real price is $135, not $100. When you compare another company's headline against ours, ask them the same question: what is the price for my number of units? Comparing one company's five-unit rate with another company's one-unit price is how a cheaper-looking quote ends up costing more.
The per-unit rate drops as you add units because the technician's travel and setup happen once per visit, however many units get cleaned. The full breakdown, and how a wash compares with a general service and an overhaul, is on our chemical wash cost page.
How to tell on the day whether you got the full job
You do not need to stand over the technician. A few things are easy to notice:
- Time on the unit. We allow 60 to 90 minutes per indoor unit, pre-check and test included. If three units are finished in well under an hour, ask what was left out.
- The drain. Ask whether the drain tray and pipe were flushed and treated, not just the coil.
- The cover came off. A wash needs the fan coil cover off to get solution into the coil. Spraying through the front grille is not a chemical wash.
- A cooling test before they leave. The unit should be switched on and the cooling confirmed before the technician packs up.
- Anything else found was quoted first. If the technician found another problem, such as low gas or a worn part, you should have been told the price before any work was done on it, not after.
Two to four weeks later, the smell test tells you the rest. A properly cleaned coil and drain should not smell musty again that quickly.
Questions to ask before you book
Send these to every company you are comparing, and compare the answers, not just the prices:
- What is the price for my number of units? Not the "from" price.
- Is that price final, or can things be added on the day?
- Is there a check first to confirm a wash is what the unit needs?
- Does the price include flushing and treating the drain tray and pipe?
- Is the solution coil-safe?
- Is there a workmanship warranty, for how long, and is it in writing?
- Is there a weekend surcharge or a transport charge?
- Do I have to sign a package or pay upfront for future visits?
Our own answers, for comparison: the price is the one on the table above, and it is final. The 9-point pre-check comes with every service booking. The drain is flushed, treated and vacuumed as part of the wash. Every wash carries a 90-day workmanship warranty. There is no weekend surcharge within standard hours (9am to 9pm Monday to Saturday, 10am to 6pm on Sunday), and transport anywhere in Singapore is included. The one exception is a restricted parking zone in the CBD or Marina Bay area, where $10 to $20 is added if commercial parking has to be paid for. We do not sell prepaid packages. Package deals are a separate subject, covered in what an advertised package price does not cover.
When the cheaper option really is the right one
Sometimes the cheapest honest answer is not to book a chemical wash at all.
If the unit does not need a wash yet, a general service is the right spend: $45 for one unit, $70 for two, $95 for three, $115 for four, and $25 per unit from five. A unit that cools normally, has no musty smell, no dripping and no visible mould, and has been serviced on a regular rhythm, is not asking for a wash. As a guide, most daily-use units in Singapore need one every 6 to 12 months, sooner if someone at home has allergies or asthma or the unit runs 8 or more hours a day.
If only one unit is the problem, you don't have to wash the whole flat. If we are already on site for another job, a chemical clean is from $100 to $150 per unit. So a general service for the rest plus a chemical clean on the problem unit is often the sensible booking. How to decide unit by unit goes through that choice in detail.
If the unit has gone years without attention, the cheap option is usually the wrong one in the other direction: a wash may not be enough, and a chemical overhaul (from $200 for one unit) takes the unit apart and cleans each component. The pre-check is what settles which of the three you need, before any money is committed.
The short version
A cheap chemical wash is only cheap if the whole job was done. The steps that usually get dropped are the check first, a coil-safe solution, a proper rinse, the drain treatment and a written warranty. Those are exactly the ones that decide whether the smell comes back in three weeks or three months. Compare quotes for your actual number of units, not the "from" price, and ask what each price includes.
If you want a straight answer on whether your unit needs a wash at all, WhatsApp us on 9107 2601. Tell us how many units you have and what they are doing, and we will confirm the exact price before anyone comes out. The full service is described on the chemical wash page, and how the check works is on the 9-point pre-check page.