Why Is Your AC Leaking Water? Understanding Common Causes and Solutions

HVAC Logo IconBy Tom MoorMarch 25, 2024
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AC leaking water

Plumbing fixtures aren’t the sole culprits when it comes to water leaks; your air conditioning unit can also be a source of unexpected pooling. HVAC.com sheds light on the common causes behind an AC leaking water and provides practical solutions to address these underlying issues, ensuring efficient and trouble-free cooling for your home.

Why Is My AC Leaking Water?

1. Clogged Condensate Drain Line

One of the most common causes of an air conditioner leaking water is a clogged condensate drain line, which funnels moisture created during the air conditioning process to the outside of your home. Over time, dirt and dust can accumulate in the drain line, obstructing the flow of water. As a result, water backs up and eventually overflows, causing leakage around the unit.

Solution: To clear a clogged condensate drain line, check for visible blockages and remove them, then use a pipe cleaner or wet/dry vacuum to dislodge debris. You can also pour a diluted vinegar or bleach solution into the pipe and flush it with water. If the clog persists, seek assistance from an HVAC contractor.

2. Damaged Condensate Pan

During the cooling process, the evaporator coil pulls excess humidity from the air. The vapor turns into water droplets that collect in a drain pan below. If the pan becomes cracked or damaged, it can allow water to escape, causing your AC to leak water.

Solution: Contact an HVAC contractor to replace the drain pan to prevent your AC from leaking water.

3. Dirty Air Filter

When your HVAC air filter becomes dirty or clogged, it restricts airflow into the system, causing the evaporator coil to freeze due to inadequate heat transfer. Eventually, when the evaporator coil begins to thaw, water will overflow the condensate drain pan and cause leakage.

Solution: To thaw the evaporator coil, turn off the air conditioner and set the system to the fan-only setting. To speed up the process, consider using a hair dryer to melt the ice. Do not use a sharp object to chip away at the ice, as it can cause damage to the evaporator coil. Regular air filter changes are essential for maintaining optimal airflow and preventing ice buildup.

4. Improper Installation

An improperly installed AC can leak water due to factors such as incorrect positioning or improper connection to components, leading to inadequate drainage that can cause water leaks.

Solution: Contact an HVAC contractor to inspect the unit and make necessary adjustments which might include repositioning the unit.

5. Refrigerant Leaks

A refrigerant leak can disrupt the system’s pressure balance, potentially resulting in the aforementioned frozen evaporator coil.

Solution: Repairing refrigerant leaks should be handled by certified HVAC professionals to ensure proper safety measures and effective resolution.

6. Malfunctioning Condensate Pump

A malfunctioning condensate drain pump can lead to water leaks in an AC system by failing to effectively remove condensate from the unit. When the pump is not functioning properly, excess moisture can accumulate and overflow, causing leaks around the system.

Solution: Inspect the pump for any signs of damage or malfunction and replace it if necessary to ensure proper drainage and prevent leaks.

7. Oversized Air Conditioner

An oversized AC unit may lead to water leakage due to short cycling, where the unit turns on and off frequently, causing excess condensation to accumulate. This excess moisture can overwhelm the system’s drainage capabilities, resulting in leaks around the unit.

Solution: Unfortunately, the only fix for an oversized air conditioner is working with a qualified HVAC technician to install an appropriately sized unit.

Regular Maintenance Can Prevent Water Leaks in Your AC System

Regular air conditioning maintenance is crucial to prevent a wide range of issues including AC water leaks. During an AC tune-up appointment, your technician will inspect, clean, and adjust all necessary components. They can also uncover issues such as a clogged drain line or refrigerant leak and make the necessary repairs before the issues become bigger and more expensive to fix.

Air conditioning maintenance should be performed once a year, preferably in the spring before you turn the system on for the first time.

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