AC Leaking Water Inside: Quick Answer
Water dripping from the indoor unit of your split AC is almost always caused by a blocked drain pipe, a dirty evaporator coil, or low refrigerant causing the coil to ice up and then drip when it thaws. All three causes can be addressed at home or with a quick service call.
Common Causes of AC Water Leakage Inside
- Clogged condensate drain pipe — algae, dirt, and slime block the drain; water overflows into the room
- Dirty evaporator coil — a dusty coil causes excess condensation that the drain tray cannot handle
- Frozen evaporator coil — ice forms due to low refrigerant or blocked airflow; melts and drips
- Disconnected or cracked drain pipe — the drain hose has come loose at the wall connection
- Incorrectly installed indoor unit — the unit is not tilted slightly backwards, so water pools instead of draining
- Low refrigerant — causes coil temperature to drop below freezing, leading to ice formation and dripping
Step-by-Step Fix for AC Water Leakage
Step 1: Clear the Condensate Drain Pipe
The most common cause. Locate the drain pipe outlet (usually on the external wall near the outdoor unit). Pour a cup of diluted bleach (1:1 with water) or white vinegar into the drain tray inside the indoor unit, or use a wet-dry vacuum on the external drain outlet to suck out the blockage. Many service engineers use a thin flexible wire or pump to clear the drain.
Step 2: Clean the Air Filter
A dirty filter restricts airflow, causes the coil to get excessively cold, and creates more condensation than the drain can handle. Remove and rinse the filters under running water. Allow them to dry fully before reinstalling.
Step 3: Check for Ice on the Indoor Unit
If you see ice on the copper pipe or inside the unit, switch the AC off immediately and run it in fan-only mode for an hour. After the ice melts, clean the filter. If icing recurs, the refrigerant level is low and a technician is needed.
Step 4: Check the Drain Pipe Connection
Inspect the drain pipe where it exits the wall. If it has slipped off its fitting or cracked, reconnect or replace it. The pipe should run continuously downhill — any uphill section traps water.
Step 5: Check Indoor Unit Tilt
The indoor unit should tilt very slightly towards the back to guide condensate into the drain tray. If it is tilted forward or is perfectly level, water can pool and overflow. A technician can re-level the unit during a service visit.
Prevention Tips
- Flush the condensate drain pipe with white vinegar every 3 months.
- Clean the air filter every 2–3 weeks during heavy use.
- Get the coil professionally cleaned once a year.
When to Call a Technician
- Drain is clear but water leakage continues.
- Ice keeps forming on the indoor coil — refrigerant leak likely.
- You notice water damage to the wall or ceiling below the unit.
- The indoor unit needs re-levelling.
Related: Sell Your Old AC in Mumbai | Sell Your Old AC in Chennai