Aircon Leaking Water? 5 Common Causes & How to Fix It Fast (2026)

By Jerry – Founder & Lead Technician at AC Service MY (12+ years experience serving KL & Selangor).

You’re relaxing at home in Seri Kembangan when you hear it: a quiet drip… drip… drip. You look up, and there’s water dripping from your air conditioner. Don’t panic! This is one of the most common aircond problems in Malaysia, and in many cases, the fix is simpler than you think.

A leaking aircon is annoying and can stain your walls or floor, but ignoring it can lead to bigger issues like mould or even electrical hazards. In this 2026 guide, we’ll walk you through the 5 most common reasons your aircon leaks water and show you exactly what to do about it.

Before you call for help, check our complete guide to 10 common aircond problems in Malaysia for a wider overview of other issues.

1. The #1 Culprit: A Clogged Condensate Drain Pipe

In 9 out of 10 cases, a water leak is caused by a blocked drain pipe. Your air conditioner doesn’t just cool the air; it also removes humidity. This water (condensate) drips into a pan and flows out through a small pipe. In Malaysia’s warm and humid climate, algae, mould, and the infamous “aircond jelly” (a thick, slimy biofilm) love to grow inside this pipe. When they build up, they create a plug. The water has nowhere to go, so it backs up and overflows from your indoor unit.

What you can do:

• Turn off your aircon.
• Locate the drain pipe. It’s usually a white PVC pipe running from the indoor unit to the outside.
• Use a wet-dry vacuum. A strong shop vacuum can often suck the clog right out from the outdoor end of the pipe.
• Flush with water. After clearing the clog, pour a mixture of warm water and a little bleach or vinegar down the pipe to kill any remaining algae. This can prevent the clog from coming back quickly.

If this doesn’t work, the blockage might be stubborn. Our technicians are experts at fast aircond repair in Kuala Lumpur and can clear even the toughest clogs with high-pressure tools.

2. Dirty Air Filters Restricting Airflow

This might sound strange—how does a dirty filter cause a water leak? When your air filter is clogged with dust, it restricts the airflow over the cooling coils. These coils get so cold that they actually freeze. When the ice eventually melts, it creates more water than the drain pan can handle, leading to an overflow.

What you can do:

• Turn off your aircon.
• Open the front panel and slide out the air filter.
• Wash it with water and mild soap. Let it dry completely before putting it back.
• Check your outdoor unit. Make sure it’s not blocked by plants or debris, as this can also restrict airflow.

Cleaning your filter every 2-4 weeks is a simple habit that prevents many problems. For more maintenance tips, read this helpful external guide on why regular AC servicing prevents major repairs.

3. Low Refrigerant (Gas) Levels

Your air conditioner uses refrigerant gas to absorb heat. If there’s a leak and the gas level drops, the pressure in the system changes. This can cause the cooling coils to get too cold and freeze up. As we learned with the dirty filters, when this ice melts, it can overwhelm the drain system and cause a leak. This is a less common cause of leaks, but it’s a serious one.

What to look for:

• Ice forming on the copper pipes of your outdoor unit.
• Your air conditioner is running but not cooling the room effectively.
• A hissing sound, which could indicate a gas leak.

Fixing a gas leak is a job for a professional. It requires special tools to find the leak and safely handle the refrigerant. To understand more about the costs involved, check our detailed guide on aircon gas top-up prices in Malaysia for 2026.

4. A Cracked or Rusted Drain Pan

The drain pan sits under your indoor unit to catch the water. Over time, especially in older units, this pan can rust through or crack. If that happens, water will simply drip out, no matter how clear your drain pipe is. You might notice rust stains on your ceiling or around the unit.

What to do:

• This usually means the drain pan needs to be replaced. In some cases, if the pan is rusted, the whole indoor unit might be ageing.
• This is not a DIY job. It requires dismantling parts of the unit.

If your unit is old, it might be time to consider an upgrade. You can get a free quote for a new aircond installation in Selangor from our team.

5. Improper Installation

If your air conditioner wasn’t installed level, the water in the drain pan won’t flow correctly toward the drain outlet. Instead, it might pool on one side and eventually spill over. This is more common than you might think, especially in older homes or with rushed installations.

What to look for:

• The leak happened shortly after a new aircon was installed.
• You can visually see that the unit is not straight.

A professional technician can re-level your unit to ensure proper drainage.

Need Fast Help with a Leaking Aircon in PJ?

If you’re in the Petaling Jaya area and dealing with a leak, our local team can help. We offer fast, reliable service and can often be at your home the same day. You can easily book a same-day aircond service in Petaling Jaya online.

When DIY Isn’t Enough

You can handle simple maintenance like cleaning filters and checking for visible clogs. But for anything involving refrigerants, electrical parts, or internal repairs, it’s always best to call a professional. Attempting complex repairs yourself can be dangerous and might void your warranty.

Our JKKP-certified technicians are trained to diagnose the root cause of any aircon problem. We use a “leak-first” approach and provide transparent pricing. If you need a trustworthy technician, don’t hesitate to contact us. Visit AC Service MY to learn more about our services.

💰 Aircon Leak Repair Cost in Malaysia (2026 Prices)

We believe in transparent pricing with no hidden fees. Here’s what you can expect to pay for common leak-related repairs:

* All prices include labor and standard materials. Final quote provided after inspection. 30-day warranty on all work.

Frequently Asked Questions About Aircon Leaking Water

Here are answers to the most common questions Malaysian homeowners have about aircon water leaks.

How do I stop my aircon from leaking water?

Start by turning off your aircon immediately to prevent further water damage. The most common fix is clearing a clogged drain pipe. You can try using a wet-dry vacuum to suck out the blockage from the outdoor end of the pipe. Also, check and clean your air filters – dirty filters can cause ice buildup that leads to leaks when it melts. If the leak continues after these simple steps, you likely have a more serious issue like low refrigerant gas or a cracked drain pan, which requires a professional technician.

For step-by-step instructions, check the 5 common causes above – we cover each fix in detail.

Can I still use my aircon if it’s leaking water?

No, you should not use your aircon if it’s actively leaking water. While it might still blow cold air, running it during a leak can cause several problems:

• Electrical hazards – Water can reach internal wiring and create short circuits or fire risks
• Ceiling and wall damage – Continuous dripping stains and weakens your home’s structure
• Mould growth – Standing water promotes mould, which affects your family’s health
• Worsening the problem – If the leak is from frozen coils, running the aircon makes the ice buildup worse

Turn off your unit, try the quick DIY fixes above, and call a professional if the leak doesn’t stop.

Is it normal for my aircon unit to leak water?

No, it is not normal for your aircon to leak water indoors. While air conditioners produce condensation as they cool (this is normal and should drain outside), any water dripping from your indoor unit means something is wrong.

A properly functioning system should have:

• ✅ No water dripping from the indoor unit
• ✅ A clear drain pipe carrying water outside
• ✅ No moisture stains on your ceiling or walls

If you see water inside, one of the 5 causes we covered needs attention.

Is an aircon leak an emergency?

It depends on the severity, but it should be treated as urgent.

Leak Type	Is It an Emergency?	What to Do
Slow drip (few drops per hour)	⚠️ Urgent, not emergency	Turn off, try DIY fixes, call within 24-48 hours
Constant dripping or streaming	🚨 YES – Emergency	Turn off immediately, call a technician today
Leak near the electrical outlet	🚨 YES – DANGEROUS	Turn off main power, call an electrician + AC tech urgently
Ceiling staining or sagging	🚨 YES – Structural risk	Turn off, move furniture, call immediately

Bottom line: Water and electricity don’t mix. If you’re unsure, turn off your aircon and call a professional for peace of mind.

Why is my aircon leaking water but still cooling?

This most often points to a clogged drain pipe. The cooling function is separate from the drainage system, so your aircon can still blow cold air even if water overflows due to a blockage. It’s like a sink with a clogged drain – water still comes out of the tap, but it overflows because it can’t go down the pipe.

How much does it cost to fix a leaking aircon in Malaysia?

The cost varies based on the cause:

• Drain pipe clearing: RM80 – RM150
• Dirty filter cleaning: Often free with service, or RM50-80 if done separately
• Gas leak repair + top-up: RM150 – RM350 (depends on leak severity)
• Drain pan replacement: RM200 – RM400
• Re-levelling/reinstallation: RM150 – RM300

We always provide a clear, upfront quote before starting any work. You can see a general overview on our complete aircond service price guide.

What causes an aircon to leak water?

The 5 most common causes are: 1) Clogged drain pipe, 2) Dirty air filters, 3) Low refrigerant gas, 4) Cracked drain pan, and 5) Improper installation. We explain each in detail in the sections above.