Aircon Leaking Water? Causes & Repair in Singapore

Why Is Your Aircon Leaking Water?

Every aircon produces condensation - that is normal. The moisture collects in a drainage pan inside the fan coil unit and flows out through a condensate drain pipe. When this system is blocked, damaged, or improperly installed, the water has nowhere to go and starts dripping from your indoor unit.

Water leaking from your aircon is more than just an inconvenience. Left unchecked, it can damage your walls, stain your ceiling, ruin furniture, and create conditions for mould growth - which is a health hazard in Singapore’s humid climate.

At Billy Aircon, we diagnose and fix the root cause of aircon water leaks, not just clear the immediate symptom. Here are the most common causes and how we address each one.

Common Causes of Aircon Water Leaks

1. Clogged Condensate Drain Pipe

The most common cause. Over time, algae, slime, and debris build up inside the drain pipe, blocking water flow. The drainage pan overflows and water drips from the unit.

Fix: We flush the drain pipe with pressurised water or use a vacuum pump to clear the blockage. For severe cases, we may disassemble the piping for thorough cleaning.

2. Dirty Air Filter

A clogged filter restricts airflow over the evaporator coil, causing it to freeze. When the ice melts, the excess water overwhelms the drainage pan.

Fix: Filter cleaning combined with a thorough inspection of the coil condition. If the coil is also dirty, a chemical wash may be needed.

3. Low Refrigerant Gas

Similar to dirty filters, low gas causes the evaporator coil to get too cold, forming ice. When the unit cycles off, the ice melts and produces more water than the drainage system can handle.

Fix: Gas top-up with leak detection to ensure the gas does not deplete again.

4. Drainage Pan Damage or Misalignment

The drainage pan can crack, corrode, or shift out of position over time - especially in older units. Water then bypasses the drain outlet.

Fix: Pan realignment or replacement. We check the gradient to ensure water flows correctly toward the drain pipe.

5. Installation Defect

If the indoor unit or drain pipe was installed without the correct gradient, water pools in the pan instead of flowing to the outlet. This is common in poorly done installations.

Fix: We adjust the unit’s mounting angle or re-route the drain pipe to achieve proper water flow.

Our Water Leak Repair Process

1. Visual inspection - We check for visible water damage patterns to narrow down the source.
2. Filter and coil check - Remove filters and inspect the evaporator coil for ice, dirt, or blockage.
3. Drain pipe test - We pour water into the drainage pan and observe flow through the drain pipe.
4. Gas pressure check - If ice build-up is suspected, we measure refrigerant levels.
5. Installation check - We verify the unit is mounted level and the drain pipe has proper gradient.
6. Root cause repair - We fix the specific problem identified in our diagnosis.
7. Verification - We run the unit and confirm no water leaks before leaving.

Emergency vs Preventative Action

Situation	Action
Water actively dripping onto furniture	Turn off the aircon immediately and contact us for same-day repair
Small moisture around the unit	Schedule a repair within a few days
Occasional water drops	Book a regular servicing - drain flushing is included
No current leak but no recent service	Book preventative servicing every 3-4 months

How to Prevent Aircon Water Leaks

Regular aircon servicing is the best prevention:

1. Service every 3-4 months - Our standard servicing includes drain pipe flushing that prevents blockages.
2. Clean filters monthly - Remove and wash your air filters at home between professional servicing visits.
3. Annual chemical wash - A chemical wash removes the deep-seated grime that regular servicing cannot reach.
4. Report issues early - Small drips become big leaks. Contact us at the first sign of moisture.

Stop the Drip - Call Billy Aircon

Do not wait for water damage to worsen. WhatsApp us now or call +65 9456 0875 for fast water leak diagnosis and repair. Same-day service available across Singapore.