Why Is Your Aircon Leaking Water?
A leaking air conditioner is one of the most common complaints we receive, and for good reason — water dripping onto your floor, furniture, or down the wall is not just annoying, it can cause real damage if left unchecked. The good news is that most water leaks have straightforward causes and can be resolved quickly by someone who knows where to look.
The most frequent culprit is a clogged condensate drain line. As your aircon dehumidifies the air, moisture collects on the evaporator coil and drips into a drain tray, which feeds into a pipe that carries the water outside or to a floor drain. Over time, algae, dust, and sludge build up inside that pipe until the water has nowhere to go — so it overflows from the tray and leaks into your room. A thorough flush with pressurised water or a wet-vac usually clears this right up.
Other causes include a cracked or tilted drain tray (common on older units), a frozen evaporator coil that melts faster than the tray can handle, a faulty condensate pump in ceiling-mounted or cassette units, or improper installation where the drain line was routed without sufficient downward slope. In rare cases, the leak may actually be refrigerant-related — ice forming on components due to low gas, then melting and dripping once the compressor cycles off.
Ignoring a water leak is risky. Beyond the cosmetic damage to walls and ceilings, standing moisture encourages mould growth behind the unit — a health concern, especially for those with asthma or allergies. Persistent leaks can also corrode the unit itself and damage electrical components. The sooner it is addressed, the simpler and cheaper the fix.
