Aircon Troubleshooting

Aircon Leaking Water Inside House? 4 Common Causes & Exact Fixes (2026)

Waking up to water dripping from your indoor aircon unit? Here is why it happens, what you can do immediately, and how to stop it permanently with a 1-month warranty.

12 September 20264 min read
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Water dripping down your bedroom wall or puddling on your wooden floor is one of the most frustrating aircon problems in Malaysia.

Because our climate in Kuala Lumpur and Cheras is hot and humid year-round, your aircon's indoor cooling coils condense litres of moisture every single day. If that water cannot drain away smoothly, it overflows into your room.

Here are the 4 most common causes of indoor aircon water leaks and how we fix them.


1. Clogged Drainage Pipe (The "Jelly Slime" Trap)

The Culprit: In Malaysia, dust particles mix with condensed moisture inside the drain pan, creating a thick, jelly-like fungal slime (lendir aircond). Over 6 to 12 months, this slime plugs the 1/2-inch PVC drainage pipe.

The Symptom: Water drips steadily from the right or left bottom corner of the indoor unit after running for 20–40 minutes.

The Fix: A high-pressure water flush combined with an antibacterial chemical clean. We blow out all accumulated slime and sanitize the drainage channel.


2. Dirty Evaporator Coils & Ice Formation

The Culprit: When filters and aluminum cooling coils haven't been cleaned in months, airflow is choked. The cold refrigerant inside the coil cannot absorb heat from the room, causing the temperature to drop below freezing point.

The Symptom: Ice forms on the aluminum fins. When you switch off the aircon or change the temperature, the ice melts faster than the drain pan can handle, resulting in sudden gushes of water.

The Fix: A full Chemical Wash (RM120–RM150). Chemical foaming agents break down grease, pet dander, and deep-seated dust between the aluminum fins, restoring open airflow and preventing frost build-up.


3. Damaged or Aging Pipe Insulation

The Culprit: Copper pipes carrying chilled refrigerant are wrapped in black foam insulation (Armaflex). Over 5 to 7 years, this insulation degrades, cracks, or gets chewed by pests.

The Symptom: Cold copper pipes come into direct contact with humid air inside your ceiling or trunking, creating condensation ("sweating") that drips onto ceiling plasterboards.

The Fix: Strip the degraded insulation and re-wrap the copper lines with high-density closed-cell insulation and vapor barrier tape.


4. Improper Drain Pipe Slope

The Culprit: Aircon drainage relies 100% on gravity. If the indoor unit was installed without a slight downward pitch, or if the PVC drain pipe bends upwards, water stagnates and backflows over the edge of the tray.

The Fix: Our technicians re-level the indoor mounting bracket and adjust the gradient of the discharge hose so gravity naturally draws water away.


Aircon Leak Repair Pricing in Cheras & Klang Valley

Service What's Included Price Warranty
Drainage Flush & General Clean Filter clean, drain pan flush, slope check RM70 flat 7 Days
Deep Chemical Wash (Canvas) Coils, fan blower, drain tray + chemical flush From RM120 1-Month Leak Warranty
Full Chemical Overhaul Complete disassembly, pipe declog, anti-mould wash From RM200 1-Month Leak Warranty

Note: For homes with 3 or more units, chemical wash drops to just RM100/unit.


What to Do Right Now (Emergency First Aid)

  1. Turn off the aircon immediately via the wall switch to prevent water from entering the electrical motor or PCB.
  2. Place a towel and bucket beneath the dripping corner to protect your floor and furniture.
  3. Inspect the outdoor drain outlet (usually outside your balcony or bathroom). If water has stopped dripping outside completely while the unit is on, your drain pipe is 100% clogged.
  4. WhatsApp Pro Aircon Service at 011-2677 0063. We offer same-day on-site slots across Cheras, Ampang, Kajang, PJ, and all Klang Valley districts.

Need a technician in Cheras or KL?

Call or WhatsApp 011-2677 0063 — we cover Cheras, Ampang, Kajang, Petaling Jaya, Shah Alam, Subang Jaya, and all of Klang Valley. Open Monday to Sunday, 8am–8pm.

Aircon down? Let's fix itAircond rosak? Mari baiki

Get a free quote in minutes.Dapatkan sebut harga dalam beberapa minit.

We reply fast, seven days a week — Mon – Sun, 8am – 8pm, all Klang Valley.Kami balas cepat, tujuh hari seminggu — Mon – Sun, 8am – 8pm, seluruh Lembah Klang.

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