Air conditioning Why is my air conditioner leaking water inside?
Water dripping from an indoor unit usually means the condensation drain is blocked or the unit is icing up, and a technician should look at it.
Water leaking inside from an air conditioner usually means the condensation is not draining away properly. Common causes are a blocked drain, ice melting off a frozen coil, or an indoor unit that is not level. Stop using the unit, keep clear of the water, and have a licensed technician find the cause.
Why does an air conditioner make water at all?
When an air conditioner cools air, moisture from the air condenses on a cold part inside the indoor unit, much like water on a cold glass. That water collects in a tray and runs away through a drain pipe, normally to the outside. In humid places like Brisbane, a working system can produce a fair amount of water every day, so the drain has to work reliably.
What are the common reasons for a leak?
- A blocked or partly blocked drain. Dust, slime or debris can stop water draining, so it overflows from the indoor unit.
- A frozen coil. If airflow is restricted or the refrigerant charge is low, ice can form and then melt faster than the drain can handle.
- An indoor unit that is not level or is poorly installed. Water can run to the wrong side of the tray and spill.
- A damaged or cracked tray or drain pipe. Older units can wear, or a pipe can be knocked or sagging.
Because a few of these causes are linked to refrigerant or electrical problems, it is not safe to treat every leak as a simple blockage.
Why is a leak more than just a wet floor?
Water near electrical parts is a safety concern. It can reach the unit’s wiring or run into a ceiling or wall, where it can damage plasterboard, insulation or other electrical items. Water running inside a ceiling can also lead to mould if it goes unnoticed. For these reasons, a leak is worth taking seriously even when it looks small.
Can I clear the drain myself?
It is not recommended. Reaching the drain and tray often means opening the unit, working near wiring, or working on a ladder or roof, and a drain that keeps blocking may point to a deeper fault such as icing or poor installation. A licensed technician can find the real cause and fix it safely.
Is the leak covered by a warranty?
It may be, depending on the age of the system and the installation. Check your paperwork and the manufacturer’s guidance, and contact the installer or retailer if the unit is new. Keep photos of the leak, since they help with any claim.
What to note before you call
Photograph the leak
Take photos from a safe distance of where the water appears and any marks on the ceiling or wall.
Write down when it happens
Note whether it leaks in cooling mode, heating mode or both, and whether it is worse on humid days.
Photograph the model label and display
Capture the make and model label and any lights or codes on the display, without touching or opening anything.
What does a technician do about a leak?
A licensed technician will inspect the indoor unit, the tray and the drain path, check whether the coil has been icing, and look at how the unit was installed. They will also check for any electrical damage from the water before the system is used again. The aim is to fix the cause, not just clear the water.
Frequently asked questions
Yes. Water draining outside, usually from a pipe near the outdoor unit, is a normal result of condensation. Leaks inside the house are not normal.
It can, if water soaks into ceilings, walls or insulation and stays damp. That is a good reason to have a leak checked early.
Summer humidity means the unit removes more moisture, so a drain that is marginal can overflow. A technician can check the drain and installation.
It is best to stop using it until it has been checked, because water and electrical parts do not mix safely.
Related services: Ducted Air Conditioning
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