Pictured above: a ceiling cassette indoor unit opened up on one of our jobs, with the blower wheel and coil exposed. A wall unit comes apart differently, but the idea is the same: an overhaul is about getting at the parts inside the indoor unit. The outdoor unit is not in the picture, and, as this post explains, it is not in the overhaul steps either.
You have two quotes for an aircon "chemical overhaul". One is a little dearer than the other, and one of them says it includes the outdoor unit. Or you are reading a quote that says "overhaul" and wondering whether the compressor box on the ledge gets washed too. The word is not defined anywhere you can look up, so the only safe way to compare is to ask what the job covers. This post sets out what an overhaul covers on our service pages, where the outdoor unit appears in our published jobs, and the questions that settle it for any company.
What our overhaul covers, line by line
Our chemical overhaul page describes a strip-down of the indoor unit. The published steps are:
- The 9-point pre-check, to confirm an overhaul is genuinely needed.
- The unit is stripped: blower, drain tray, casing and covers removed.
- Every component is cleaned individually with specialised chemicals, not just rinsed in place.
- The blower wheel is cleaned and re-balanced.
- The PCB and electrical parts are inspected and dust-cleared.
- Anti-rust coating is applied to the metal components.
- The drain tray and pipe are pressure-cleaned and treated.
- Full reassembly, then a 5-point performance test before we leave.
Read that list for the words "outdoor", "condenser" or "compressor". They are not there. The overhaul page does not mention the outdoor unit at all. Every step is something done to the indoor unit, which is why the price is counted per indoor unit and why the published time is about 2 to 3 hours per indoor unit. A full 3-unit HDB flat is usually a half to a full day, depending on access and the condition of the units.
Where the outdoor unit does appear in what we publish
It appears in two places, and in both it is a look rather than a wash.
| Published job | What it says about the outdoor unit | Look or wash? |
|---|---|---|
| 9-point pre-check (on every booking) | "Outdoor condenser inspection": a visual check of the fan, the condenser coil and the external pipework, to catch fan failure and coil corrosion early | A look |
| General servicing ($55 for 1 unit) | The service page lists a basic check of cooling, electrical connections and the outdoor unit | A look |
| Chemical wash (from $135 for 1 unit) | Not mentioned. The steps are the roller, a water tray and cover, chemical on the coil and blower, rinse, drainage flush, cooling test | Not covered |
| Chemical overhaul (from $200 for 1 unit) | Not mentioned. The steps are the eight above, all on the indoor unit | Not covered |
So the honest summary of our published position is this: the outdoor unit is inspected on every visit, and none of our published wash or overhaul steps clean it. We have not published a price for washing an outdoor unit, so we will not give you one here. If an outdoor unit needs more than a look, that is a conversation after the pre-check, with a quote before any work starts, not a number you can read off this page.
Why the outdoor unit matters to people who ask
The reasoning behind the question is sound. The outdoor unit is where the heat from your rooms is pushed out, and a coil coated in dust or cooking grease has a harder job doing it. On a ledge that is crowded or boxed in, the unit can end up breathing its own hot air. Nobody sees any of it from inside the flat, so the first sign is usually a bill or a unit that struggles on a hot afternoon.
Two things follow from that, and neither needs a wash. First, the cheapest improvement is free: clear the ledge. Brooms, pots, drying racks and stored boxes are the most common thing a technician has to move before he can reach the unit, and they sit exactly where the condenser needs air. Second, the pre-check's outdoor inspection exists to tell you whether yours needs anything at all. If the technician reports a caked coil or corrosion, you will have a finding to act on rather than a guess. A rusting bracket is a separate matter again, covered in when a rusting condenser bracket has to be replaced.
The price line that hides the scope question
Our overhaul prices are $200 for 1 indoor unit, $370 for 2, $515 for 3 and $640 for 4, then $150 for each unit from the fifth onwards. The chemical wash is $135 for 1, $245 for 2, $345 for 3 and $425 for 4, then $100 per additional unit. All of it is counted per indoor unit. A System 3 is three indoor units and one outdoor unit, and its overhaul is $515: there is no separate line for the outdoor unit, because the job does not include one.
That is the detail to carry into a comparison. If one quote is $515 for a System 3 and another is noticeably higher with "outdoor unit included", the extra may be real work or may be a differently worded package. You cannot tell from the total. You can tell by asking for the lines. We cannot say what any other company includes under the same word, and we are not going to guess. The question to put to them is whether the outdoor unit is in the price, what is done to it, and whether that is written on the quote.
Five questions that settle it
- Which parts come off the indoor unit? A real overhaul names the blower wheel and the drain tray. "Full chemical treatment" does not.
- Is the outdoor unit washed, or only inspected? Ask for one word, and ask for it in writing. "Checked" and "cleaned" are different promises.
- If it is washed, what is the method and what is the price? A price for the outdoor unit should appear as its own line, so you can see what you are paying for.
- Can the technician reach it? If your outdoor unit sits on a ledge that is hard to reach, say so when you book. Access can change how and when the work is done, and it is better settled before the day.
- What does the warranty cover? Ours is 90 days on workmanship for chemical wash and chemical overhaul. Ask what it is on the other quote, and ask whether it covers the outdoor work too.
Our guide to reading a general service checklist line by line applies the same habit of reading the verbs to servicing quotes, and the questions above are the overhaul version of it.
Whether you need an overhaul at all
The outdoor-unit question is easy to over-weight, because the real decision is whether the indoor unit needs stripping. Our overhaul page lists the cases: an aircon more than 5 years old that has never had an overhaul, a unit with a persistent smell or weak cooling that came back soon after a chemical wash, heavy mould or grime visible on the blower wheel or inside the casing, and water that keeps overflowing despite drainage cleaning. For most homes it is every 2 to 3 years, with routine servicing and a chemical wash in between.
If none of that describes your unit, a chemical wash from $135 may be the right job, and the pre-check will say so. We will not strip a unit that only needs a wash. And if you have already paid for an overhaul and want to know whether it was done, how to check an overhaul was really done sets out what you can see on the day without any technical knowledge.
The short version
- On our pages the chemical overhaul is a strip-down of the indoor unit. The outdoor unit is not in the published steps.
- The outdoor unit is inspected or checked, not washed, in the 9-point pre-check and the general service. We publish no price for washing it.
- Prices are per indoor unit, so a System 3 overhaul is $515 with no outdoor line. An extra line on another quote is a scope question to ask about.
- Clear the ledge before any visit. It costs nothing and it helps the unit whatever job you book.
- Ask for "washed or inspected" in writing, from any company.
Every price above comes from our pricing page, and the overhaul steps from the chemical overhaul page.
If you would like a straight answer for your system
Tell us how many indoor units you have, whether it is an HDB flat, condo or landed home, when the unit was last washed, and what it is doing. A photo of the outdoor unit on its ledge helps us see what we are dealing with. The 9-point pre-check, including the outdoor inspection, tells us which job your unit needs, and we quote before any work starts. WhatsApp us on 9107 2601 and we will tell you what to expect before we come.