Aircon Water Leaking? Here Are the Most Common Causes & Fixes
Water dripping from your indoor aircond unit is one of the most common problems in Malaysia. Here's what causes it and how to fix it properly.
Why Is My Aircon Leaking Water?
Water leaking from your indoor unit is the most common aircond complaint in Malaysia — especially during rainy season. Here are the main causes.
Cause 1: Blocked Drain Pipe
The most common cause. Algae, mould, and debris clog the drain pipe. Solution: Drain pipe flush during basic service or chemical wash.
Cause 2: Dirty Evaporator Coil
When the coil is coated with dirt, excess condensation forms and drips. Solution: Chemical wash or overhaul.
Cause 3: Ice on the Coil Melting
If the coil freezes (due to low gas or severe blockage) and then melts, a large amount of water drips suddenly. Solution: Check gas levels and clean the coil.
Cause 4: Damaged Drain Pan
Over time, the plastic drain pan can crack. Solution: Drain pan replacement during an overhaul.
What to Do Right Now
- Place a bucket or towel below the unit to protect floors and furniture
- Turn off the aircond if leaking heavily to avoid electrical risk
- Do NOT seal the leak with tape — water will back up into electrical components
- WhatsApp KL Renovator at +60 18-298 3573 with a description or short video of the leak
Same-day slots frequently available. See: Aircond Water Leaking Help | Complete Overhaul Service
Cost to Fix a Leaking Aircond
Most water leaking issues are resolved during a chemical wash (from RM 120) which clears blocked drain pipes — the most common cause. If the drain pan is cracked or the unit has not been serviced in years, a chemical overhaul (Wall-Mounted Aircon only, from RM 420) addresses all internal causes comprehensively. Acting quickly prevents secondary water damage to walls, ceilings, and floors that can cost far more than the service itself.
Prevention
The best way to prevent water leaking is consistent maintenance. A drain pipe flush every 3–4 months as part of basic servicing (RM 99) prevents algae and mould blockages from forming. An annual chemical wash removes biofilm buildup that basic servicing cannot reach. Most leaking cases in Malaysia happen because the drain pipe has been left unserviced for 18 months or more.
Same-day slots frequently available. WhatsApp +60 18-298 3573.
Can You Fix It Yourself?
The only DIY step worth attempting is checking the outdoor drain pipe outlet — if it is visibly blocked by debris at the exit point, clearing it may resolve minor dripping. For anything more than this, professional service is recommended. Attempting to dismantle the indoor unit, modify the drain pipe, or seal the leak with tape risks causing additional damage. The cost of a professional drain pipe clearing (included in a RM 99 basic service) is far less than the cost of repairing water damage to walls or ceilings caused by a persistent leak.
Definitions
Key terms in this guide, explained
Short, plain-language definitions of the terms used above — written by the technicians who do the work, not copied from a manufacturer brochure.
What is the evaporator coil?
The evaporator is the finned coil inside the indoor unit where cold refrigerant absorbs heat and moisture from the room air. Because it is permanently wet during operation, it is where mould, bacteria and dust bind together into the grey film that causes the sour smell and the drop in airflow. Filters catch the coarse dust; the coil holds the rest.
If the airflow feels weak right after a filter wash, the coil — not the filter — is the blockage, and that needs a chemical wash.
What is pump-down when relocating an aircond?
Pump-down is how refrigerant is saved before a unit is taken off the wall: the technician closes the liquid valve, runs the compressor briefly so the gas collects in the outdoor unit, then closes the suction valve and disconnects the pipes. Skip it and the whole charge vents to atmosphere, so the reinstall needs a full recharge you then pay for.
Ask whether the quote for dismantling includes pump-down and a new flare set; those two items decide whether the reinstall cools properly.
Chemical overhaul — what is dismantled?
A chemical overhaul is the level above a chemical wash: the indoor unit is dismounted, dismantled into casing, blower wheel, drain tray and coil, and each part is soaked and scrubbed separately before reassembly and a leak test. It is the only way to clear a drain tray that has silted up or a blower wheel packed solid with mould. Published price starts at RM 420 for 1.0–1.5 HP.
Ask for an overhaul instead of another wash if the unit still drips or smells within weeks of a chemical wash.
Side-by-side comparison
Chemical wash vs basic servicing: what does each one clean?
Both are cleaning visits, but they clean different parts of the unit and are not interchangeable.
| What to compare | Pressure chemical wash | Basic servicing |
|---|---|---|
| What gets cleaned | Coil, blower wheel, drain tray, filters | Filters, panel, drain flush, outdoor coil brush-down |
| Fixes smell and weak airflow | Yes — that is the point of it | Only if the filter was the blockage |
| Time on site | 45–90 minutes per unit | 20–30 minutes per unit |
| Published price (1.0–1.5 HP) | RM 120 | RM 99 |
In short: Book basic servicing on a 3–4 month rhythm; book a chemical wash when the smell, the airflow or the water dripping tells you the coil itself is loaded.
Quick answer
KL Renovator's practical answer: Water dripping from your indoor aircond unit is one of the most common problems in Malaysia. Here's what causes it and how to fix it properly.
Reader FAQs
Why Is My Aircon Leaking Water?
Water leaking from your indoor unit is the most common aircond complaint in Malaysia — especially during rainy season. Here are the main causes.
Can You Fix It Yourself?
The only DIY step worth attempting is checking the outdoor drain pipe outlet — if it is visibly blocked by debris at the exit point, clearing it may resolve minor dripping. For anything more than this, professional service is recommended.
Reviewed by real technicians
KL Renovator's HVAC Expert Team
This article links back to the same field team that services wall-mounted, ceiling cassette and window units across KL & Selangor. Meet the 4 real technicians behind KL Renovator, see their experience, and review our service standards before you book.
