How long does a chemical overhaul take?

Typically 90 to 120 minutes per indoor unit. The exact time depends on unit type, contamination level, and access. Ceiling cassettes and concealed units take longer due to access requirements.

How is a chemical overhaul different from a chemical wash?

In a chemical wash, the evaporator coil is treated in place — the unit stays on the wall. In an overhaul, the indoor unit is fully removed, disassembled, soaked, and flushed component by component. Overhaul is appropriate when contamination is too heavy for in-place cleaning to clear properly.

How often should a unit be overhauled?

Most units on a regular service schedule do not need a chemical overhaul every year. After a proper overhaul, the next one is typically needed every 2 to 3 years depending on usage and how consistently the unit is serviced in between.

Will a chemical overhaul fix my aircon if it is not cold?

It will fix cooling problems caused by contamination. If the cooling issue is a refrigerant fault, electrical fault, or mechanical failure, the overhaul will not address it. We assess this before starting.

Do you need to move furniture or cover anything?

We protect the floor and nearby surfaces before starting. Because the unit is removed from the wall, the area below needs to be clear for us to work. We confirm the site requirements when you book.

Aircon Chemical Overhaul in Singapore

A chemical overhaul takes the indoor unit off the wall and breaks it down for cleaning. Components are soaked and flushed rather than treated in place — the step up when a chemical wash is not enough.

Signs the unit may need a chemical overhaul

A chemical overhaul is not the starting point for most units. These patterns suggest that contamination has gone beyond what an in-place chemical wash can clear.

Problems returned quickly after a recent chemical wash
Thick, visible mould growth inside the unit casing
Heavy black or brown deposits on the blower fan wheel
Persistent smell even after multiple cleans
Unit not cleaned for several years
Post-renovation with heavy dust and debris inside the casing

What happens during a chemical overhaul

Unlike a chemical wash, an overhaul involves removing the indoor unit from the wall entirely. Every internal part is disassembled, soaked, and flushed before the unit is rebuilt and reinstalled.

1. Document condition and disconnect
We photograph the unit condition before touching anything. The indoor unit is powered down, refrigerant connections are disconnected, and the unit is carefully removed from the wall bracket.
2. Full disassembly
The casing, blower wheel, evaporator coil, drain pan, and all internal components are disassembled. Each part is examined to assess contamination level and condition before cleaning begins.
3. Soak and chemical treatment
Components are soaked in a chemical cleaning solution to break down compacted mould, biofilm, and dust deposits. The blower wheel — typically the most contaminated part — gets dedicated attention.
4. Flush and rinse all components
Every component is flushed under running water to clear the chemical agent and dislodged deposits. The coil is rinsed thoroughly to remove all chemical residue before reassembly.
5. Reassemble, reinstall, and test
The unit is reassembled, remounted on the wall bracket, and reconnected. We run a full operational test covering airflow, cooling, and drainage before the job is signed off.

What changes after a chemical overhaul

Blower fully cleared

The blower wheel accumulates the densest deposits over time. Full removal and soaking clears buildup that no in-place method can reach, restoring airflow to near-new levels.

Mould eliminated at the source

Heavy mould growth on internal surfaces is removed completely, not just reduced. The smell and contamination that drives it are cleared rather than managed.

Coil efficiency restored

The evaporator coil is fully accessible during overhaul. The soak and flush removes deposits from the entire coil surface, restoring heat-transfer performance.

Extended service interval

A properly overhauled unit starts from a genuinely clean baseline. On a regular service schedule, the next overhaul is typically not needed for several years.

Chemical overhaul rates

Per-unit rates for standard wall-mounted units up to 12,000 BTU. Ceiling, ducted, and higher-capacity units carry a $10/unit surcharge.

1 unit — $150/unit
2 units — $125/unit
3 or more units — $115/unit

Booking and visit timing

Chemical overhauls are scheduled with lead time to plan access. The unit comes off the wall, so the work area below needs to be clear.

Around 90 minutes to two hours per unit
The work area below the unit must be clear for removal
Multi-unit overhauls may run across a full day
We confirm the date and any access requirements before the visit

What a chemical overhaul covers

A chemical overhaul includes everything in a chemical wash, plus full unit disassembly, soak treatment, and component-level cleaning. It takes longer and costs more because the scope is genuinely different.

Indoor unit removed from wall bracket
Full disassembly of casing, blower, coil, and drain pan
All components soaked in chemical cleaning solution
Each component flushed and rinsed thoroughly
Blower wheel cleaned individually
Unit reassembled, remounted, and tested before leaving
Any parts showing wear or damage flagged before job is closed

When overhaul is necessary — and when it is not

Not every unit needs an overhaul. Most units on a regular service schedule never reach the contamination level that justifies it. Recommending an overhaul when a chemical wash would suffice is scope that does not benefit the customer.

Overhaul is appropriate when contamination is heavy enough that in-place cleaning will not clear it fully
If the unit has been serviced regularly, a chemical wash is usually sufficient
If symptoms returned quickly after a chemical wash, overhaul is the next step
We assess contamination level on-site before recommending overhaul
We will not recommend it if a chemical wash will do the job

When overhaul should not be the first step

A chemical overhaul addresses contamination. It will not fix refrigerant faults, electrical problems, motor failures, or control issues. If the unit is showing fault symptoms alongside contamination, the fault should be investigated before the overhaul is booked.

Sudden cooling loss independent of contamination
Error codes or blinking display lights
Breaker trips or electrical smell
Outdoor unit not running
Unit that was recently overhauled but stopped cooling shortly after

General service, chemical wash, or chemical overhaul?

Overhaul is the deepest level of cleaning but not the right level for most units. The table below shows where each level applies.

Service type	Typical scenario
General service	Unit cooling normally, serviced within the last 6 months
Chemical wash	Weak airflow, persistent smell, or 6+ months overdue
Chemical overhaul	Heavy mould, thick contamination, or issues returning quickly after a wash

What customers say

I recently engaged their service for a chemical overhaul of my aircon, and I'm extremely pleased with the experience. Denni and Yi Da took the time to explain what they were doing at each stage.

zulkhairil zulhanif

Engaged snowflake services for aircon chemical overhaul and they did a really good job in cleaning the units, the aircon's have never been so clean before!

Deborah L

Engaged them for chemical cleaning for 5 x FCU and compressor cleaning. They are very meticulous and professional in carrying out the job.

Azhar Md Saleh

When the units were opened and looked into, we found mould. We did the chemical wash and steam cleaning — the technicians explained everything they were doing and why.

Anisah Ahmad

Chemical overhaul FAQ

Ready to book a chemical overhaul?

Tell us the unit count, system type, and the last time the unit was properly cleaned. We will confirm whether a chemical overhaul is the right level — or whether a chemical wash will do.

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