Water coming out of an indoor unit is always a drainage or an airflow problem. Here they are in the order you should check them.
1. Blocked drain line, which you can often fix yourself
The most common cause by a wide margin. Dust and biological growth block the condensate line, water backs up in the pan and overflows. If the line is accessible, clearing it may be enough. If it runs inside a wall, call someone.
2. Dirty filter
A clogged filter starves the coil of air, the coil drops below freezing, ice forms, and when the unit stops the ice melts faster than the pan can drain. Wash or replace the filter and run the unit with the cover off to watch what happens.
3. Drain pan cracked or misaligned
Plastic pans crack with age and UV exposure, and a unit that was never mounted level will overflow at one corner regardless of how clear the drain is. Both need a technician.
4. Low refrigerant
An undercharged system runs the coil colder than design, ice forms, and you get the same melt-and-overflow. Low charge means there is a leak somewhere, and topping it up without finding the leak just delays the same call.
5. Condensate pump failure
Where the unit is below the drain point, a small pump lifts the water out. When it fails, the pan fills within hours.
When to stop and call
Turn the unit off if water is reaching electrical components or a ceiling. Water plus electricity is not a diagnostic exercise. Give us a call and we will take a look. It is usually a short visit.
Want this checked properly?
A free on-site assessment takes about 30 minutes and tells you exactly what the system needs, and what it doesn't.
