Your AC’s inside unit contains the evaporator coil (pictured on the right) that cools the warm air blown over it. This causes condensation (moisture) to form on the coil, just like how water droplets form on a cold glass of water on a hot day.
The moisture on the coil drips into a drain pan and down a condensate drain line (a white PVC pipe) that leads out your home.
So, with all that in mind, here are a few things that cause that water to leak into your home.
Cause 1: Clogged condensate drain line
A clogged condensate drain line is the most common cause of water leaking from your AC into your home.
If the drain line gets clogged with dust, dirt, sludge or mold, that water backs up into your home. In that case, you’ll need to unclog it. There are multiple unclogging methods, like using a wet/dry vac on the condensate line.
But the surefire way is to have a professional use a special vacuum to suck the blockage material out.
Cause 2: Damaged/rusted drain pan
Got an old air conditioner (12-15 years)? The drain pan may be damaged or rusted through, so water just falls right through. You’ll need to replace the pan.
Cause 3: Broken condensate pump
Is your furnace and indoor AC unit installed in the basement? If so then there is a condensate pump that pumps the water outside. But if the pump breaks, the water isn’t being pumped outside anymore. You will need to repair or replace the pump.
Cause 4: Dirty air filter
A dirty air filter blocks air flow over the evaporator coil. When that happens, the evaporator coil gets too cold and freezes over. When it melts, it drips an excess amount of water that the pan may not be able to handle.
Check your air filter to see if it’s dirty and change it if needed. You should be changing it every 1-3 months (depending on the season).
Cause 5: Low refrigerant
Similar to a dirty air filter, the low refrigerant will lower pressure in the AC system, causing the evaporator coil to freeze over. When the coil melts, water overflows the drain pan.
You’ll notice you’re low on refrigerant when:
- The air conditioner isn’t cooling well
- You hear a hissing or bubbling noise (indicating a refrigerant leak)
Depending on the severity of the refrigerant leak you’ll either repair the leak or replace the whole AC unit.
If you need a new one, read our article, “My Air Conditioner is Dying, and I Need a New One…Now What?”
Need an AC Repair Expert?
If changing the air filter did not help, contact Cool Today to repair your air conditioner.
Also, ask us about installing a float switch on your air conditioner if it does not have one already. This switch will shut down the air conditioner in case it overflows with water again.