Why Is My AC Leaking Water?
Your AC leaks water when the condensate drain line is clogged, the drain pan is cracked or overflowing, or the evaporator coil is frozen and melting faster than the pan can handle. A clogged drain line is the most common cause — you can often fix it by pouring a cup of distilled vinegar down the line or using a wet/dry vacuum to clear the blockage.
THE DETAILS
Your AC removes humidity from indoor air as part of the cooling process. That moisture collects on the evaporator coil, drips into a drain pan, and flows out through a condensate drain line. When any part of this system gets blocked or damaged, water backs up and leaks.
The most common cause is a clogged condensate drain line. Algae, mold, and debris build up inside the line over time. You can clear it by pouring a cup of distilled vinegar down the drain access point (usually a PVC pipe near the indoor unit) or using a wet/dry vacuum on the outdoor end of the drain line.
A cracked or rusted drain pan is another common cause, especially in older units. The primary pan sits under the evaporator coil — if it has cracks or rust holes, water drips through instead of flowing to the drain line. Replacement is straightforward for a tech.
A frozen evaporator coil that melts can overwhelm the drain pan. If you see ice on the coil or refrigerant lines, turn the AC off, set the fan to ON, and let it thaw. Check your air filter — a clogged filter is the most common cause of coil freezing.
A dirty or clogged air filter reduces airflow and can cause both freezing and excess condensation. Replace it every 1-3 months during cooling season.
🔧 WHEN TO CALL A PRO
Call a pro if the leak continues after clearing the drain line, if you see ice on the coil repeatedly, if the drain pan is cracked or rusted, or if water is leaking near electrical components. Water near electrical parts is a safety hazard.