Why Is My AC Unit Leaking Water?

Air conditioning water leakage is something no homeowner wants to deal with — especially in the middle of an East Tennessee summer. While it might seem like a minor issue, it could point to a more serious problem.

Spotting the warning signs early can help you avoid expensive AC repairs or replacements, prevent water damage to your home, and keep your air conditioner running smoothly through the summer heat and humidity.

Common Causes of AC Water Leaks

If your AC is leaking water, it’s not recommended to continue using it until you have a certified HVAC professional inspect your system. There are several common reasons your AC might be leaking:

Clogged Condensate Drain Line

The condensate drain line carries away the excess moisture your system removes from the air during the cooling process. But when dirt, mold, or debris block the line, that water has nowhere to go and ends up overflowing near your unit.

If you see pooling water or damp spots near your AC, a clogged condensate drain line is a likely suspect.

Frozen Evaporator Coils

Another common cause of an AC leaking water is frozen coils. Evaporator coils help cool the air and freezing can be caused by restricted airflow from dirty filters or blocked vents.

Once the system cycles off and the ice melts, excess water can spill out of the unit. Signs of frozen coils include reduced airflow, ice buildup around the indoor unit, or unusual hissing noises.

Low Refrigerant Levels

Low refrigerant can also cause the evaporator coils to freeze. Low refrigerant might be a sign of a leak somewhere in the system, which requires professional intervention from a licensed HVAC technician, since handling refrigerant requires special certification.

If your AC isn’t cooling as effectively as it used to — or if it’s making bubbling or hissing sounds — you may need a professional to check your refrigerant levels.

Damaged, Full, or Rusted Drain Pan

Over time, your AC’s condensate drain pan that collects the condensation can fill up or develop cracks and rust. When that happens, even a small amount of normal condensation can leak out instead of being drained.

If you see a steady drip from the bottom of your system, a damaged or full drain pan might be to blame.

Malfunctioning Condensate Pump

Some ACs — particularly those installed in basements or attics — use a condensate pump to move excess water, or condensate, away from the unit. If the pump fails, water will back up and leak out. A malfunctioning pump can be due to electrical issues, dirt buildup, or a faulty float switch.

Troubleshooting Tips for Homeowners

In less serious cases, a little DIY investigation can save you time and money. If the leaking is severe, turn the system off right away to prevent further damage. Then, try these quick steps:

• Check and replace the air filters.
• Inspect for visible debris, clogs, or water near the unit.
• Make sure your thermostat settings aren’t overworking the system.
• Clean around the condensate drain line (if accessible).

When To Call a Professional

When an AC problem goes beyond what you can handle on your own, a licensed and certified HVAC technician can make sure the issue is properly diagnosed and repaired.

Here are some signs it’s time to call for a professional AC repair:

• The leak persists after basic troubleshooting.
• You see ice anywhere on your AC unit.
• You suspect you may have refrigerant issues.
• Water damage is visible or spreading.
• Regular AC maintenance hasn’t been done in over a year.
• You suspect your AC unit wasn’t installed properly.

Preventing Future AC Water Leaks

The best way to avoid a leaky air conditioner is through regular preventative maintenance. Industry experts recommend scheduling biannual inspections with a licensed HVAC technician, who can clean internal components, check refrigerant levels, and test for potential issues before they become costly problems.

By scheduling regular AC maintenance, you can help increase energy efficiency, lower your utility bills, improve your home’s air quality, extend the lifespan of your unit, and ensure warranty compliance.

Keep your AC’s air filters clean between maintenance visits and replace them monthly during high-use seasons to maintain proper airflow and prevent frozen coils. You can also consider installing a float switch — a device that automatically shuts the unit off when excess water is detected.

Choose Pipe Wrench Plumbing, Heating & Cooling

If you’re dealing with a persistent AC leak in your Knoxville-area home, you don’t have to resolve the problem on your own. Whether it’s a clogged condensate drain, frozen coils, or something more serious, Pipe Wrench Plumbing, Heating & Cooling can help with expert AC services.

We offer a same-day service guarantee, meaning we get the job done right the first time. With decades of trusted experience, top-quality materials, and award-winning customer service, we’re Knoxville’s go-to team for reliable HVAC solutions.

Our team is dedicated to providing the best customer service in the Greater Knoxville, TN, area, and we’ve been voted “one of the top heating and cooling companies” in Knoxville for seven years, so contact us for expert HVAC services.

Contact Pipe Wrench Plumbing, Heating & Cooling today to schedule a fast, professional AC repair in Knoxville, TN.