Chemical Wash vs Chemical Overhaul: How to Choose the Right Service for Your Singapore Home
You know your aircon needs more than just a normal “general servicing.” Perhaps it is not blowing cold air, it smells musty, or it is dripping water onto your bed. When you look at service menus from Singapore aircon companies, you often see two confusingly similar options: “Chemical Wash” and “Chemical Overhaul.”
What exactly is the difference? Why does one cost significantly more than the other? And which one do you actually need? This comprehensive guide will help you make the right decision so you don’t overpay for service you don’t need, or worse, under-service a unit that needs critical help.
Understanding the Difference: It’s All About the Depth
Option A: Chemical Wash (The “Deep Clean”)
What happens: During a Chemical Wash, the technician keeps the aircon unit mounted on your wall. They remove the outer plastic cover and the filters. A large, specialized “catchment bag” (like a giant funnel) is strapped underneath the unit to catch all the dirty water.
The technician then uses a chemical solution spray to soak the evaporator coils and the fan blower. After the chemical breaks down the dirt, they use a water spray to rinse it off. They also vacuum the drainage pipe to clear blockages.
Best for: Units that are moderately dirty, have not been serviced for 6-9 months, or have a slight smell. It is a good “maintenance” deep clean to do once a year to keep the unit efficient.
Option B: Chemical Overhaul (The “Full Surgery”)
What happens: This is a much more intensive procedure. The technician first “pumps down” the refrigerant gas into the outdoor compressor to save it. Then, they completely disconnect the aircon fancoil unit from the wall.
They take the entire unit to your toilet or service yard. Every single part is dismantled—the drainage tray, fan motor, blower wheel, evaporator coil assembly, and even the circuit board (PCB) is removed. Each part is chemically treated and washed individually with high pressure. It is essentially stripping the unit down to its bare bones and rebuilding it.
Best for: Units that are severely clogged, leaking water badly due to stubborn “jelly” buildup, have not been serviced in over a year, or have serious mold issues. It is also the only solution if the water leak is caused by a “back tray” choke, which cannot be reached while the unit is on the wall.
Detailed Comparison Table: Wash vs. Overhaul
| Criteria | Chemical Wash | Chemical Overhaul |
| Procedure | Unit stays mounted on the wall | Unit taken down completely |
| Cleaning Depth | Reaches ~70-80% of visible parts | Reaches 100% of all parts (Front & Back) |
| Time Required | 30 – 45 minutes per unit | 1.5 – 2 hours per unit |
| Price Range (HDB/Condo) | $$ (Moderate: ~$80-$100) | $$$ (Higher: ~$130-$180) |
| Solves Jelly/Choke? | Partially (Front tray only) | Completely (Guaranteed for Front & Back) |
| Fan Motor Cleaning | Surface wipe only | Removed, lubricated & deep cleaned |
| Gas Check | Pressure check included | Pump down & Top-up check included |
Decision Checklist: Which One Do You Need?
Choose Chemical Wash if:
- Your air flow is slightly weak, but not zero.
- There is a mild musty smell that goes away after a few minutes.
- You have been doing regular general servicing but missed the last 1-2 appointments.
- The unit is relatively new (less than 3 years old).
- You want a thorough clean but are on a tighter budget.
- Check our Chemical Wash page for current promotional rates.
Choose Chemical Overhaul if:
- Water is leaking heavily from the back of the unit (near the wall).
- The fan blower is visibly caked with thick, black dust or mold.
- The airflow is almost zero even on “High” fan speed.
- You have not serviced the unit for more than 12-18 months.
- You have pets (cats/dogs) – fur clogs the deep internals quickly.
- The unit is older (5+ years) and has never had an overhaul.
- Someone in the house has severe allergies or asthma.
- Learn more on our Chemical Overhaul page.
Our Professional Recommendation for Singapore Homes
At GoodCool SG, we believe in transparency and honest dealing. We often arrive at a customer’s house booked for an expensive Overhaul, but after inspection, we tell them a cheaper Chemical Wash is enough. We will never sell you a service you do not need.
The “Reset” Strategy:
If you are moving into a resale HDB or condo, we recommend considering a Chemical Overhaul for all units before you move in. You don’t know the maintenance history of the previous owner. An overhaul gives you a “fresh start”. It sanitizes the unit completely and makes it run like new.
Electricity Savings:
An overhaul can also help reduce your SP Services bill. A choked fan motor and blocked coil force the unit to run at maximum power to cool the room. After an overhaul, the unit runs more smoothly and cools faster, which can help reduce energy consumption.
Still Unsure? Let Us Check For You
You don’t have to be the expert. That’s our job. Our experienced technicians can assess your unit on-site. We will shine a torch inside, check the airflow, and recommend the best solution for your specific situation. We provide a warranty for water leakage on both services.