Possible causes if the indoor unit leaks water
| Cause | How to tell | What to do |
|---|---|---|
| Clogged drain pan or hose | Water drips especially after long running | Clearing and cleaning the drain (service) |
| Crushed hose or reverse slope | Started after a new installation or relocation | Correcting the hose route and slope |
| Dirty filter | Airflow is weak, filter is dusty | Filter cleaning (can be done at home) |
| Low refrigerant | Cooling is weak; water overflows as the coil ices up and thaws | Leak detection and refrigerant charging |
| Installation slope | Indoor unit hung perfectly flat or tilted the wrong way | Mounting adjustment |
| Drain pump fault | Water from the ceiling on cassette and ducted units | Pump and float check |
Is your air conditioner leaking water?
Tell us the unit type and the symptom; let's schedule service to check the drain and refrigerant.
Is it normal if the outdoor unit leaks water?
In heating mode, the outdoor unit defrosts from time to time and water runs from underneath; this is normal. Water from the outdoor unit in cooling mode usually happens because the indoor unit's drain hose was routed next to the outdoor unit. Where the water goes on the balcony and facade needs to be planned at installation.
Should I keep running a leaking air conditioner?
Water can damage the electrical installation, the wall and your belongings. We recommend switching the air conditioner off and protecting the area underneath until the problem is solved. Jobs other than filter cleaning should be done by service. As a precaution, have regular air conditioner maintenance done; for the steps, see our article on how to clean and maintain an air conditioner. For the same problem in fan coils in large buildings, you can read our fan coil faults article.
Frequently asked questions
Why does an air conditioner leak water?
In the indoor unit, the most common cause is a clogged drain. A dirty filter, icing caused by low refrigerant, a crushed hose and a wrong installation slope can also make it leak.
Is water from the air conditioner outdoor unit normal?
It is normal during defrost in heating mode. In cooling mode, it is usually the indoor unit's drain water.
Can I clear my air conditioner's drain myself?
You can check whether the hose end is crushed or blocked; cleaning the indoor unit pan and the line is a job for service.
Does a leaking air conditioner mean low refrigerant?
It can, but it is not the only cause. The drain and filter are checked first, then a pressure measurement is taken.