Aircond Leaking Water? Causes, Repair and Price in KL & Selangor
A wall-mounted aircond in Malaysia can pull several litres of water out of the air on a humid afternoon. All of it is supposed to run down the drain pipe and outside. When you see water dripping from the front of the indoor unit, running down the wall, or pooling on the floor, that drainage path has failed somewhere. This page explains the causes we actually find on site, which checks you can safely do yourself, and what the repair costs.
The six causes we actually find
1. Blocked condensate drain line
This is the most common cause by a wide margin in KL and Selangor. Condensate runs continuously through a small-bore drain pipe. Over months, dust from the room combines with the damp inside that pipe and grows a biofilm, and in older installations algae and insect nests build up at the outdoor end. Once the pipe is restricted, water backs up into the drain tray and overflows at the lowest point of the front edge, which is why the drip usually appears from one corner of the indoor unit. Clearing the line properly means flushing it through and cleaning the tray, not just poking the outdoor end.
2. Dirty evaporator coil and blower wheel
When the coil fins are matted with dust and biofilm, condensate no longer runs cleanly down the fins into the tray beneath. It clings to the fouled surface and gets picked up by the airflow, so the unit spits water forward out of the louvres instead of draining it. You will usually notice weaker cooling and a musty smell at the same time. The fix here is a proper dismantled clean rather than a drain clear: see aircond chemical wash for what that involves and chemical wash vs normal servicing for which one your unit needs.
3. Cracked, displaced or overflowing drain tray
The drain tray sits under the coil and catches the condensate. Trays crack with age and with rough handling during previous servicing, and on some models the tray can be knocked out of position when the casing is refitted. A cracked tray drips from the centre or the back rather than from a corner, and no amount of drain clearing will fix it. Tray replacement depends on the model and is quoted on site.
4. Indoor unit installed off-level, or the wrong drain gradient
The indoor unit needs a slight tilt toward the drain outlet, and the drain pipe needs a continuous fall to the outside with no rising section and no sagging loop. Installations that were rushed, or units that have been re-hung after a wall repaint, often end up level or tilted the wrong way. The tell-tale sign is a unit that has leaked intermittently since the day it was fitted, or since it was last moved, rather than one that developed a leak after years of service. Correcting this means re-levelling the unit and re-running or re-supporting the drain line.
5. Ice building up on the coil, then melting
If the coil ices up, the ice melts when the compressor stops and dumps far more water at once than the tray can hold. Icing has two usual causes: airflow starvation from a blocked filter or a failing blower, or a low refrigerant charge. Low refrigerant is itself a symptom, because refrigerant is not consumed in normal operation — if it is low, it has leaked out. Repeatedly topping the gas up without finding the leak means paying for the same job again in weeks. See aircond gas refill and leak diagnosis for how the pressure and leak test works.
6. Uninsulated or poorly insulated pipework
Sometimes the water is not coming from the drain at all. Refrigerant lines run cold, and in Malaysian humidity any bare section of copper or any gap in the pipe insulation will sweat heavily and drip. This shows up as water at the pipe run or behind the unit rather than at the tray, and the fix is re-insulating the exposed section.
What you can safely check yourself
- Wash the filters. Slide them out, rinse, dry fully, refit. A choked filter starves airflow and is a genuine cause of icing. This is the one check that is both safe and often effective.
- Look at the outdoor drain outlet. With the unit running, water should be dripping steadily out of the drain pipe outside. No water outside while water appears inside means the line is blocked.
- Check for a sagging or kinked drain pipe. A visible loop in the pipe holds water and stops the flow.
- Look for frost. Ice or frost on the coil or on the copper pipe at the outdoor unit points to airflow or refrigerant problems, not a drain blockage.
When to stop and call a technician
Call rather than continue if any of the following apply: the leak continues after the filters have been washed and dried; you can see ice on the coil or pipework; the water is dripping from the middle or the back of the unit rather than a front corner; there is water near electrical fittings or tracking into a ceiling; the unit is also cooling poorly or smells musty; or the unit is a ceiling cassette or ceiling exposed type, where the tray, the drain pump and the float switch are all above your head and awkward to reach safely.
What we do on a water-leak call
- Free checking. The technician runs the unit, finds where the water is actually coming from, and tells you the cause before quoting.
- Drain line flushed through and the tray cleaned out, with the float switch tested where the unit has one.
- Coil and blower condition assessed. If the coil is the cause, we quote a wash rather than pretend a drain clear will hold.
- Unit level and drain gradient checked, and corrected if that is what is causing it.
- Pressure and leak test if there is any sign of icing, so a refrigerant leak is not missed.
- Run the unit again and confirm the water is draining outside before we leave.
What it costs
Checking is free, and so is normal travel within our coverage area. What you pay depends on what is causing the leak.
Full price list: aircond service price in KL & Selangor.
Warranty
Leak repairs carry a 30-day leak warranty: if the same leak returns within 30 days of our visit, we come back at no extra charge. Other work carries. Replacement parts are covered by the manufacturer warranty, which varies by part and brand. Terms are written on the receipt.
Frequently asked questions
Why is my aircond dripping water inside the room?
In Malaysia the usual cause is a blocked condensate drain. The indoor unit pulls a lot of moisture out of humid air, and that water has to run out through a drain pipe. When dust, biofilm or algae block the pipe or the drain tray, the water backs up and spills over the front of the tray into the room. A dirty evaporator coil produces the same result, because water beads on the fouled fins and gets blown past the tray instead of dripping into it.
Can I fix an aircond water leak myself?
You can safely do three things: switch the unit off at the wall so water stops being produced, put a towel or basin under the drip, and take out the filters and wash them. Anything past that means opening the casing, handling the drain tray or clearing the drain line, which is where people crack the tray or break the float switch. If washing the filters does not stop the leak within a day, the drain line or the coil needs to be cleared properly.
Does an aircond water leak mean the gas is low?
Usually not, but it can be. Low refrigerant makes the evaporator coil run cold enough to form ice. When the unit switches off, the ice melts all at once and overwhelms the drain tray, so you see a sudden burst of water rather than a steady drip. If your unit is also cooling poorly, or you can see frost on the coil or the copper pipe, the leak is a symptom and the refrigerant charge is the real problem. That needs a pressure and leak test, not just a gas top-up.
How much does it cost to fix an aircond that leaks water?
Checking is free. If the fix is a drain clear and clean, it is usually done as part of a service: a normal water-based wash is RM90 per unit, and a full chemical wash is RM130 for 1.0 HP, RM150 for 1.5 HP, RM180 for 2.0 HP, RM200 for 2.5 HP and RM250 for 3.0 HP and above. If a part has failed, such as a drain pump or a cracked tray, or the indoor unit has to be re-levelled, that is quoted on site before any work starts.
Is water leaking from the aircond dangerous?
The water itself is condensate, not clean drinking water, and it often carries mould and bacteria from the coil, so it should not be left to soak furnishings. The bigger risks are practical: water running down a wall damages plaster and paint, water tracking into a ceiling void can reach light fittings, and a persistent damp patch will grow mould. Switch the unit off and stop it producing more water while you wait for a technician.
What warranty do you give on a water-leak repair?
Leak repairs carry a 30-day leak warranty. If the same leak comes back within 30 days of our visit we return at no extra charge. New parts fitted during the job are covered by the manufacturer warranty, which varies by part and brand.
Related pages
- Aircond repair in KL & Selangor - free checking, repair quoted on site
- Aircond chemical wash - from RM130 per wall-mounted unit
- Aircond gas refill and leak diagnosis - why a pressure test beats a blind top-up
- Aircond service price list - every published price in one place
- Cassette aircond service - ceiling units, drain pumps and float switches
- Aircond not cold? 7 causes - if cooling has dropped off as well
Service areas
We handle water-leak calls across KL and Selangor, including Old Klang Road and OUG, Puchong, Petaling Jaya, Shah Alam, Ampang, Kepong, Cheras and the rest of our coverage area.