Aircond Leaking Water (Bocor Air): 5 Real Causes and How to Fix Each

If your home aircond has started dripping water onto the floor, staining the ceiling below, or pooling under the indoor unit, the good news is: the unit isn't broken. It's telling you one of five specific things is wrong. Here's what each looks like and how a proper aircond repair fixes it.

1. Blocked drainage line (the most common cause)

Every indoor aircond unit has a small drain pipe that carries condensation water outside. Over months, dust, algae and mould build up inside that pipe until water can no longer flow through it. When that happens, the water backs up inside the unit and drips out from the front instead.

How Marvel fixes it: Flush the drainage line end-to-end with a proper drain-cleaning kit, then verify the water runs clear at the outdoor discharge point. This is part of every chemical service we do.

2. Cracked or displaced water tray

Underneath the cooling coil sits a plastic water tray that catches condensation before it enters the drain pipe. If the tray cracks (usually from old age) or shifts out of position (usually after a bad prior service), water spills over the edge instead of flowing to the drain.

How Marvel fixes it: Realign or replace the tray. On some Panasonic and Daikin units the tray is a separate part; on others the whole cooling module comes out. Quoted before we start.

3. Frozen cooling coil, thawing out

If the cooling coil ices up during operation (usually because the filter is clogged or the refrigerant is low), and then the aircond is turned off, the ice melts all at once — far more water than the drain tray can handle. That water spills forward, onto your floor.

Two things need fixing: the reason it iced up (dirty filter or a slow gas leak needing a leak-check topup) and often a proper chemical service to clear the coil.

4. Poor installation slope

The indoor unit has to be installed at a very slight tilt so water drains toward the pipe outlet, not toward the front of the unit. Some installers rush this and mount the unit dead level. Water then finds the front edge and drips out.

How Marvel fixes it: Remount the bracket at the correct slope. This is the reason we spend proper time on aircond installation — a fast install now becomes a bocor call in six months.

5. Refrigerant leak causing low pressure

Less common, but real: a slow refrigerant leak causes the coil to run colder than it should, which leads to freezing and thawing (see cause 3), which leads to water dripping. The water is a symptom; the leak is the cause.

How Marvel fixes it: Pressure-test to find the leak, repair the leak point, then top up the gas. See our gas topup with leak check for how that process works.

What you should not do

Don't put a towel under it and hope it stops. Water dripping from an aircond eventually finds its way into ceiling voids, stains gypsum, warps wooden floors, and grows mould on plaster. It gets worse, not better.

Book a proper diagnosis

If your aircond is leaking, WhatsApp us a short video of where the water is coming from. In most cases we can tell you the likely cause before we even arrive, so the visit stays short and the quote is clear before any work starts.

Straight into the repair queue: our aircond repair page shows the diagnostic fees by unit type, and the fee is credited toward the repair if you proceed.