1. Clogged air filter
Dust blocks airflow, so the coil gets too cold and frosts over. When the frost melts, water overflows the drain tray.
How we fix itFilter wash in a general serviceAircon servicing from $54.50 →
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Why Is My Aircon Leaking Water?
Most leaks come from a dirty filter, a blocked drain pipe or mould in the drain tray. Here's how to tell which one it is, what you can check yourself, and when to call us.
The short answer
An aircon usually leaks water because condensation can't drain away. The most common causes are a clogged air filter, a blocked drain pipe or mould build-up in the drain tray. Cleaning the filter is a safe first step. If it still drips, the unit needs servicing or a chemical overhaul.
Quick diagnosis: what is your aircon doing?
| What you notice | Likely cause | Fix | Cost |
|---|---|---|---|
| Drips from the front, filter looks dusty | Clogged air filter | Clean filter (DIY) or general servicing | Free / from $54.50 |
| Steady drip from the bottom of the unit | Blocked drain pipe | Drain flushing during servicing | from $54.50 |
| Leak plus musty smell or black spots | Mould in coil and drain tray | Chemical overhaul | from $150 |
| Ice on the coil, then water as it melts | Low refrigerant gas | Gas top up and leak check | from $100 |
| Leaks soon after a new installation | Unit not level or poor pipe slope | On-site check and re-levelling | $80 diagnosis* |
Prices before GST. *On-site diagnosis is $80 for a split system and is waived when you book the repair.
5 common causes of a leaking aircon, and how to fix each
2. Blocked drain pipe
Slime and dirt build up inside the drain pipe. Water backs up and drips out of the indoor unit instead.
How we fix itPump and flush the drain pipeAircon servicing from $54.50 →
3. Mould in the coil and drain tray
In Singapore's humidity, mould grows inside the unit and clogs the tray. A normal service can't reach it.
How we fix itFull dismantle and chemical soakChemical overhaul from $150 →
4. Low refrigerant gas
Low gas makes the coil freeze. The ice melts when the unit cycles off and overflows the tray.
How we fix itLeak check and gas top upGas top up from $100 →
5. Poor installation
If the indoor unit tilts the wrong way or the drain pipe doesn't slope down, water can't flow out.
How we fix itRe-level unit, re-route pipingAircon repair: $80 diagnosis →
What you can check yourself
- Switch off the aircon at the wall isolator.
- Remove and rinse the filters under the tap, then let them dry fully.
- Check the drain pipe outlet outside for blockage or kinks.
- Look at the indoor unit to see if it tilts forward.
- Run it for 30 minutes and see if the drip stops.
Don't open the unit or spray chemicals into it yourself. Water near wiring is a safety risk.
Aircon leaking water: FAQs
How much does it cost to fix a leaking aircon in Singapore?
At JL Aircond, most leaks are fixed with general servicing from $54.50 or a chemical overhaul from $150 per unit, before GST. The $80 diagnosis fee is waived if you book the repair.
Can I still use my aircon if it's leaking?
It's best to switch it off until the leak is fixed. Water can stain walls, damage flooring and drip onto power points.
Is a leaking aircon dangerous?
The water itself is only condensation, but it becomes a safety risk if it reaches sockets or extension cords. Damp walls can also grow mould.
How do I stop my aircon from leaking again?
Wash the filters every few weeks and service the aircon regularly so the drain pipe is flushed. Most Singapore homes service every 3 to 4 months.
Aircon still leaking? We'll fix it.
Send a photo or video of the leak on WhatsApp. We'll tell you the likely cause and give you a quote.