Water Leaking
Why water may be appearing around your indoor HVAC equipment
Your air conditioner normally removes moisture from indoor air and safely drains that water away. A puddle or active leak around the indoor unit is not normal and usually means condensation is not draining properly, the evaporator coil has frozen, or part of the drainage system needs attention.
5 Common Reasons Your AC May Be Leaking Water
Open each section to understand where the water may be coming from and why your air conditioner may not be draining properly.
1 Clogged condensate drain line A blocked drain can cause condensation to back up and overflow near the indoor unit.
What’s happening?
As your AC cools the air, moisture condenses on the evaporator coil and drips into a drain pan. That water normally leaves the system through the condensate drain line.
Why can this cause a water leak?
Over time, dust, dirt, biological growth, and other debris can build up inside the drain line. If the line becomes blocked, water can back up into the drain pan and eventually overflow instead of draining safely away.
If water is actively leaking or pooling around the indoor unit, switch the cooling system OFF to help prevent additional water damage. Avoid opening equipment panels. A clogged or slow drain should be properly cleared and tested for drainage.
2 Cracked, rusted, or overflowing drain pan The drain pan must collect condensation and direct it into the drain line without leaking.
What’s happening?
The condensate drain pan sits beneath the evaporator coil and catches the moisture produced during normal cooling operation.
Why can this cause a water leak?
Over time, a drain pan can corrode, crack, become damaged, or collect enough debris to interfere with drainage. Water may then leak through the damaged pan or spill over its edge instead of reaching the drain line.
If you can see standing water around the indoor equipment without removing panels, turn the system OFF and protect the surrounding floor or ceiling area from additional water. Drain-pan inspection and repair should be handled by an HVAC professional.
3 Frozen evaporator coil A frozen indoor coil can release more water than the drainage system can handle when the ice begins to melt.
What’s happening?
The evaporator coil should be cold during normal cooling, but it should not become covered with ice. Restricted airflow, a dirty filter, a dirty coil, blower problems, or refrigerant-related issues can allow the coil temperature to fall low enough for moisture to freeze on it.
Why can this cause a water leak?
When that ice eventually melts, a large amount of water can enter the drain pan in a short period of time. If the pan or drain line cannot handle the water properly, it may overflow and create a puddle near the indoor unit.
If you see ice on the evaporator coil or refrigerant lines, switch the thermostat from COOL to OFF. Do not chip, scrape, or try to force the ice off the coil. Have the reason for the freeze-up professionally diagnosed.
4 Low refrigerant or a refrigerant leak Low refrigerant can contribute to evaporator-coil freezing and water leakage when the ice melts.
What’s happening?
Refrigerant circulates through a sealed system and allows the evaporator coil to absorb heat from your indoor air. The system should not normally consume refrigerant during operation.
Why can this cause a water leak?
When refrigerant charge is too low, often because of a leak, operating pressures and coil temperatures can fall outside the proper range. The evaporator coil may frost or freeze, and the melting ice can later appear as water around the indoor equipment.
Low refrigerant is not a homeowner repair. If you see coil icing, notice reduced cooling, or suspect a refrigerant problem, switch the cooling system OFF and schedule professional diagnosis.
5 Drainage or installation problem Condensation must be directed from the coil into the pan and through a properly installed drain system.
What’s happening?
The drain pan and condensate piping are designed so water flows away from the indoor unit. The drain line needs the proper routing and slope, and the coil and equipment must be installed so condensation reaches the pan correctly.
Why can this cause a water leak?
A disconnected drain pipe, improper slope, incorrect equipment positioning, or another drainage installation problem can prevent condensation from flowing where it should. This is especially worth checking if leaking began after recent installation or service.
Do not reposition the equipment or modify the drain piping yourself. If the leak began after installation, equipment replacement, or recent HVAC work, have the drainage setup inspected and corrected.
Your AC naturally creates condensation, but that moisture should be collected and drained safely away. Active leaking should be addressed promptly to reduce the risk of equipment or property damage.