Why is my aircon leaking water

Water dripping from a wall unit is condensate that cannot drain away. The tray fills and overflows into the room. The usual cause is a choked condensate line; less often a cracked tray or a drain run without enough fall.

What actually happens

• A choked condensate line is the most common cause by a wide margin.
• A cracked or misaligned drip tray leaks even when the line is clear.
• A run with insufficient gradient will keep re-choking after every clear, which is more common in older retrofitted piping.
• Switch the unit off if it is dripping onto electrics or flooring, then get the line cleared.

Questions people ask

Does a leaking aircon mean it needs gas?

No. Leaking water is a drainage fault. Refrigerant is a separate system, and a low-gas unit shows as poor cooling, not as water.