What Causes Water Leakage from Indoor Aircon Units in Singapore
Introduction
In Singapore’s tropical humidity, it’s common to spot a puddle of water forming under your air conditioner. Many homeowners panic when they notice their indoor aircon unit dripping, fearing a major breakdown. But don’t worry — water leakage is one of the most frequent and fixable aircon issues in Singapore.
The key is understanding why it happens. This guide explains the main causes of indoor aircon leaks, how to identify early warning signs, and what you can do before calling in professionals like ACX for help.
Singapore Context: Why It Happens More Often Here
Singapore’s warm climate and high humidity make aircon condensation natural. When air passes over the cold evaporator coil, moisture from the air condenses into water, which should drain smoothly through a pipe.
However, local factors often make leakage more likely:
- Constant use: Many homes run the aircon 8–12 hours daily.
- Humidity: The air holds more moisture, increasing water formation.
- Dust accumulation: Urban dust and haze particles clog drainage systems faster.
- Compact HDB layouts: Shorter air paths mean warmer indoor airflow, causing more condensation.
So while a bit of condensation is normal, dripping water from the indoor unit isn’t — it signals a drainage or airflow issue.
Why It Matters
Ignoring a leaking aircon can lead to more serious problems:
- Water stains or peeling paint on your walls.
- Mould growth in the surrounding area.
- Short-circuit risks if water reaches wiring.
- Reduced cooling efficiency.
A minor leak today can become a costly coil replacement tomorrow. That’s why identifying the cause early is crucial.
Main Causes of Aircon Water Leakage
1. Clogged Drainage Pipe
This is the most common cause in Singapore. The drain line carries condensed water from the evaporator coil to the outside of your home. Over time, dust, algae, or even lizard droppings can block the pipe, causing water to overflow inside.
Signs:
- Dripping water from the front panel.
- Gurgling sound when aircon runs.
- Water pooling under the unit.
Fix:
A technician will use a wet vacuum or pressure pump to clear the drain pipe and flush the line with cleaning solution.
2. Dirty Air Filters
When filters are covered in dust, airflow is restricted, causing the evaporator coil to freeze. When it melts, excess water overflows from the drip tray.
Signs:
- Weak airflow even at high fan speed.
- Ice forming on the coil.
- Water dripping a few hours after turning off the aircon.
Fix:
Clean your filters every 3–4 weeks with mild soap and water. If leaks persist, a coil wash may be needed.
3. Damaged or Misaligned Drain Pan
The drain pan collects condensation before sending it to the pipe. Over time, it can rust, crack, or shift out of place — especially in older units.
Signs:
- Slow, irregular dripping.
- Water leak near the rear of the indoor unit.
- Aircon works fine otherwise.
Fix:
Replacement or resealing of the drain pan is required.
4. Improper Installation or Tilt
If your indoor unit isn’t level, water can’t flow naturally toward the drainage pipe. It pools at one side, leading to leakage.
Signs:
- New aircon starts leaking within a few weeks of installation.
- No dust blockage or odour issues.
Fix:
Technician adjusts the mounting bracket or support so the unit tilts slightly toward the drainage pipe (about 5–10 degrees).
5. Low Refrigerant Gas
When refrigerant levels are low, the pressure drops and the evaporator coil gets too cold — causing frost buildup that later melts into excess water.
Signs:
- Weak cooling despite long run time.
- Hissing noise from indoor unit.
- Periodic dripping after defrosting.
Fix:
Technician checks for leaks and performs a gas top-up. Always request a leak test before refilling refrigerant.
6. Dirty or Blocked Evaporator Coil
A dusty coil disrupts normal condensation and drainage. Moisture collects unevenly and eventually drips where it shouldn’t.
Signs:
- Musty smell from aircon.
- Visible dirt or mould near vent.
- Irregular dripping pattern.
Fix:
Professional chemical cleaning or coil wash — a service offered by ACX — restores proper airflow and drainage.
Step-by-Step: What Technicians Do to Fix a Leak
| Step | Task | Purpose |
|---|---|---|
| 1 | Inspect filters and coil | Identify airflow restriction |
| 2 | Check drainage system | Detect blockages or misalignment |
| 3 | Vacuum or flush drain pipe | Remove dirt, algae, and insects |
| 4 | Clean evaporator coil | Improve condensation flow |
| 5 | Test for gas pressure | Ensure correct cooling performance |
| 6 | Run final leak test | Verify drainage and cooling balance |
Each service usually takes 30–90 minutes, depending on unit condition.
Preventive Maintenance Tips for Singapore Homes
- Clean filters regularly — every 3–4 weeks.
- Schedule professional cleaning — general servicing every 3–6 months, chemical cleaning once a year.
- Keep windows closed — reduce humid air entering your room.
- Check for early signs — weak airflow or gurgling sounds are early warnings.
- Book reputable technicians — providers like ACX ensure drain pipes are flushed properly during each visit.
Cost of Fixing Aircon Water Leaks in Singapore
| Service Type | Average Cost (SGD) | Description |
|---|---|---|
| Drain pipe vacuuming | $50–$80 | Clears clogs and removes slime |
| General aircon cleaning | $60–$90 | Prevents coil and filter buildup |
| Chemical wash | $120–$180 | Deep clean to stop recurring leaks |
| Drain pan replacement | $100–$150 | For older or corroded units |
| Gas top-up | $40–$80 | Fixes low pressure and frost leaks |
Most water leakage problems are solved within a single servicing session, especially if caught early.
Key Benefits of Prompt Repair
| Benefit | Description |
|---|---|
| Prevents mould and stains | Keeps walls and furniture dry |
| Saves on electricity | Restores normal compressor performance |
| Extends aircon lifespan | Reduces strain on parts |
| Improves air quality | Stops stagnant water and bacteria buildup |
| Avoids costly repairs | Prevents damage from persistent leaks |
FAQs
1. Why does my aircon leak only sometimes?
It could be due to fluctuating humidity or a partially clogged drain. Have it inspected before it worsens.
2. Is water leakage dangerous?
It can be if water reaches electrical parts. Switch off your aircon and call a technician immediately.
3. Can I fix a leaking aircon myself?
You can clean filters and check drainage alignment, but avoid dismantling parts — that’s for professionals.
4. How often should I service my aircon to prevent leaks?
Every 3–6 months for general cleaning and once a year for chemical cleaning.
5. My aircon leaks after a chemical wash — why?
If the drainage system wasn’t flushed properly afterward, residual blockage could cause it. Contact the service provider for a check.
6. Will topping up gas stop water leakage?
Only if low refrigerant caused coil freezing. Otherwise, cleaning is required.
7. How can I tell if my drain is blocked?
You’ll often hear gurgling sounds or see dripping after turning off the aircon.
Conclusion
Water leakage from your indoor aircon unit might look worrying, but it’s usually a simple fix once the cause is identified. Most leaks come from clogged drain pipes, dirty filters, or misaligned pans — all easily handled by a professional.
To prevent future leaks, combine regular filter cleaning with professional servicing. ACX offers reliable aircon inspection and cleaning services across Singapore, ensuring your system runs cool, clean, and drip-free all year round.
