Why Is My LG Aircon Leaking Water, and When Did It Start?

Every cooling cycle pulls water vapour out of the air in your room and condenses it on the LG's coil. A tray beneath collects the runoff, and a pipe takes it outside. That pipe has a speed limit.

Most indoor leaks are not a sealed-off pipe. They are a drain path clearing water slower than the coil is making it. The tray fills, the level reaches the lip, and the surplus goes over the edge.

That is why the room still gets cold while the unit drips. Cooling is working. The water that cooling produces has nowhere to go quickly enough.

Two questions do more work here than any inspection. What date did the first drip appear, and who had their hands in the unit shortly before that date.

A unit that has dripped since it was new has a routing problem. A unit that started days after someone worked on it has a reassembly problem. A unit that only leaks in bad weather has a load problem. Three different jobs.

Only one common cause behaves the way owners expect. A true blockage drips every time the unit runs, from the first minute, and the weather makes no difference to it.

Rain outside and water inside sound unrelated. Humidity is the link. Damp air carries more moisture, the coil pulls more of it out, and the tray fills faster than on a dry day.

A storm therefore asks the drain for more than it has ever delivered. A path that copes with an ordinary afternoon can fall behind in one that is genuinely wet.

Ceiling cassettes and ducted units have one more part in that path. They sit above the drain, so a pump and a float switch lift the water out. Wall units usually fall away by gravity alone.

The float switch has a trigger level, and that level can sit slightly high. The pump then starts on time on ordinary days and late on the heaviest ones. Water passes the tray lip before the pump catches up. Nothing has failed, and the ceiling is wet anyway.

Drain faults are usually put there by hand. A pipe does not develop a wrong angle on its own, and a seated fitting does not work itself loose.

On a new install the usual error is fall. The line needs a steady drop along its full run, not only at the point it leaves the unit. One short uphill stretch looks fine while volumes are low, and pools once daily use raises them.

That explains a new unit that runs dry for weeks and then starts dripping. Nothing changed inside the unit. The amount of water going through it changed.

After a service or chemical wash the usual error is reassembly. A hose goes back at a shallower angle, a cover sits slightly out of line, a fitting stops just short of home. It passes the visual check and shows itself on day three or four.

If either date fits yours, say so plainly when you call. Give the date of the work, then the date you first saw a drip. Ask for the drain path and its connections to be checked before parts are quoted. Reassembly slips are ordinary, and whoever did the work is usually quickest at putting one right.

The drain path gets cleared or ruled out before the unit is opened. It takes minutes, and it holds the answer in most cases.

Fall comes first. The line is followed from the tray outlet to wherever it discharges, looking for any stretch running level or uphill. A dip holds water and a rise stops it.

Connections come next. Every joint gets checked for full seating, including the inlet at a pump chamber on units that have one.

Then it is run under load. Cooling carries on until the coil is producing condensate at a realistic rate, and someone stays with the outlet for that whole period. A drain that swallows a poured jug can still fall behind the volume a working coil makes on a humid day.

A tray, a pump or a coil becomes a fair question only after those three. A quote that opens with one of them has skipped the cheap part.