Water dripping from a split AC indoor unit is most often caused by a clogged drain pipe, a frozen evaporator coil from dirty filters or low gas, or wrong installation slope. Switch the AC off, check the filter and drain, and call a technician if it keeps dripping.
Water dripping from your split AC’s indoor unit can stain walls, ruin furniture and create mould. The good news is that the causes are limited, and most are fixable. Here is how to find yours.
Why the AC makes water in the first place
An air conditioner cools the air by passing it over a cold coil. Moisture in the air condenses on that coil like water on a cold glass. It is collected in a tray and flows out through the drain pipe. Anything that stops this path, or makes the coil freeze, can cause water to drip into the room.
Common causes
1. Clogged or kinked drain pipe
Dust, algae and debris can block the drain pipe, so water backs up and overflows from the indoor unit. A pipe that is kinked, flattened or lifted too high also stops proper flow. This is the most common cause.
2. Dirty air filter or evaporator coil
Poor airflow makes the coil too cold. It freezes over, and when the ice melts the tray cannot handle the volume. Clean the filters, and if the leak returns, book a deep clean.
3. Low refrigerant
Low gas drops the coil temperature far below normal, which causes icing. If you see ice on the pipe or the coil together with weak cooling, suspect a leak. Read about AC gas refill and leak checks.
4. Wrong installation slope
The indoor unit must be installed slightly tilted towards the drain side, and the drain pipe must slope downwards all the way out. Poor installation, especially after shifting or reinstalling an AC, often leads to leaks.
5. Damaged or cracked drain tray
Older ACs can develop cracks in the drain tray, which let water escape from the unit.
6. Poor insulation on the pipes
Worn insulation on the copper pipe can cause condensation to form along it and drip, especially in humid weather.
7. Very humid weather
During monsoon, the AC removes much more moisture. A drain that was borderline can start overflowing.
What you can do right now
- Switch off the AC and put a bucket or towel under the drip. Switch off power to the unit if water is near electrical parts.
- If there is ice on the coil or pipe, run the fan only until it melts.
- Clean the filters and let them dry.
- Look at the drain pipe outside. Is it flowing, blocked, kinked or pushed into standing water?
- Check the indoor unit is not visibly tilted the wrong way.
Do not use the AC repeatedly while it is leaking, and do not poke inside the unit.
When to call a technician
- The leak returns after cleaning the filter
- Ice forms again on the pipe or coil
- Water drips near electrical parts or from the display
- The AC was recently installed or shifted
- You are unsure where the water is coming from
A technician can clear the drain line, clean the coil, check the gas and correct the slope.
How to prevent leaks
- Clean filters every few weeks in season.
- Book a yearly service, with a deep clean before summer. See AC service types and cost.
- Use an experienced installer who checks the drain slope.
- Keep the drain outlet free of dirt and out of standing water.
AC leak repair in Thane, Kalwa and Mulund
We fix water leakage, clean drain lines and reinstall ACs correctly. Check our AC repair service, or WhatsApp us a photo of the leak.