Is Your Air Conditioning Leaking Water? Here Are 8 Possible Causes

An air conditioner (AC) keeps your house cool and comfortable by pulling heat and humidity from the air. As the AC extracts humidity from the air, it produces condensate, or water, in your furnace or air handler. This water is normally kept in a drain pan and sent through piping into your home’s drain system.

Unfortunately, damaged pipes or sludge buildup can cause the piping to become backed up. When this happens, water backs up in the drain pan within your furnace or air handler. It can then reach your home. This is decidedly troublesome if your furnace or air handler is located in the attic or above a finished ceiling.

In most homes, local codes necessitate a secondary or safety drain pan that is put underneath the furnace or air handler. This secondary drain pan possesses piping that is routed to the outside of the home. Typically, the outlet of the pipe is located above the outside of a window so it’s quickly noticeable if water is draining from this pipe outlet. It is not normal for this to occur. If you see water leaking from piping on the outside of your home, this is often an indication the primary drain is backed up and water is now draining from the safety drain pan.

Here are the most general causes for why your AC is leaking water and how to fix the issue. Some homes will also use a safety device that should automatically switch off your AC in the event the drain becomes clogged. In this case your system will stop cooling except if the drain is cleaned of any obstructions. Regardless, if you find water leaking, ensure you set your thermostat to “off” to prevent any further water damage and call a Service Experts Heating, Air Conditioning & Plumbing service provider to correct the issues.

Leaking air conditioners often demand professional help, which is why we’re here to assist you at Service Experts Heating, Air Conditioning & Plumbing. We proudly deliver Expert air conditioning repair across North America, backed by a 100% Satisfaction Guarantee.*

1. Condensate Drain Is Blocked

When hot, humid air runs along the evaporator coil, water appears on the cold metal surface. In the end, the water drains into a pan under the indoor coil in the furnace or air handler. As the cooling sequence takes place, the condensate flows out of the pan and into drain piping before the pan overflows.

However, mold, mineral deposits, dirt and other debris can clog the drain. This prevents the water from flowing away like it’s supposed to. Leave the unclogging process to an Expert like Service Experts Heating, Air Conditioning & Plumbing to guarantee it’s completed properly and without causing further damage. Service Experts can also install a safety device that will quickly turn off your AC just in case the drain becomes blocked again sometime after, thus preventing water damage within your home. Of course, consistent maintenance on your AC will help keep your condensate drain clean and open.

2. Drain Line Is Disconnected

While unusual, the drain line connection to the drain pan may become loose or disconnected. This may be the cause if someone is working close to the unit or when changing out the air filter. AC leaks may occur when the drain line breaks free from the pan. Check your AC to determine if the drain line is still connected to the coil drain pan. If it is no longer connected, we suggest calling an HVAC technician to resolve this issue immediately. Make an appointment with Service Experts Heating, Air Conditioning & Plumbing today.

3. Condensate Pump Isn’t Working

Some air conditioners require a condensate pump to properly drain the water. These pumps are needed when the home’s drain system is located above the AC unit. Even if the drain is free of obstructions, water could back up in the pan and leak out if the condensate pump is damaged. First, double-check that the pump is being powered. If that’s not the case, the AC leak may be due to a broken condensate pump. You should check with an air conditioning contractor like Service Experts Heating, Air Conditioning & Plumbing to resolve the issue.

4. Evaporator Coil Is Dirty or Broken

If you see little drips rather than a more substantial puddle nearby the outside of your furnace or air handler, water might be bouncing off the evaporator coil instead of properly draining into the drain pan and condensate line. This can happen if the coils are grimy, or if holes in the insulation smartest approach to prevent the evaporator coil from going downhill is to keep up with annual air conditioning maintenance using a Service Experts Heating, Air Conditioning & Plumbing membership.

5. Low Refrigerant Level

If you discover a leak and the AC isn’t cooling enough, the refrigerant level may be lacking thanks to a leak. Air conditioners use refrigerant to create cold air, so getting it inspected regularly during seasonal maintenance is incredibly useful for the working condition of your unit. Without a full supply of refrigerant, the evaporator coils may freeze over and cause the drain pan to overflow as they thaw. Contrary to some expectations, your AC does not need to be refilled unless there is a leak. The system is sealed and recharging is only needed when a leak happens in the system. Call Service Experts Heating, Air Conditioning & Plumbing as soon as you can to take care of AC refrigerant issues quickly.

6. Dirty Air Filter

Your air conditioner’s filter should be changed regularly to produce enough airflow. Without adequate ventilation, the evaporator coils could become too cold and freeze. The evaporator coils will then thaw, causing excess water to fill in the drain pan—sometimes producing an overflow. To resolve this, try changing your air filter. If the problem doesn’t go away, additional repairs might be required. Fortunately, HVAC technicians from Service Experts Heating, Air Conditioning & Plumbing are here to serve you, ensuring the problem gets resolved.

7. Outdoor Temperature Is Too Cold to Run AC

Air conditioners are built to be used during warm weather. Using your AC when outdoor temperatures are 60 degrees Fahrenheit or below will sometimes cause the evaporator coils to freeze. Once thawed, the water and ice will drop off the evaporator coils and possibly result in an overflow thanks to ice blocking the drain pan opening. If a water leak persists, schedule a Service Experts Heating, Air Conditioning & Plumbing technician backed by our 100% service guarantee* to help solve the problem.

8. Damaged Drip Pan

Air conditioners are designed to last, but nothing survives forever. If you own an AC that is 12 years or older, the drip pan may be damaged or corroded due to normal use. If the drain pan has holes in it, a water leak could appear as condensate seeps directly through it. Service Experts Heating, Air Conditioning & Plumbing can replace the drain pan and ensure your AC gets back to working like it’s supposed to.

Our Experts Can Tackle All Your Air Conditioning Repair Needs

Whatever the reason why your AC is leaking water, Service Experts Heating, Air Conditioning & Plumbing can fix the problem. We’ll troubleshoot and fix your air conditioner, getting it back to running again right away.

Our technicians are highly trained, knowledgeable and certified to perform quality work. We have full confidence in our repairs—in fact, we back up everything we perform with a one-year 100% Satisfaction Guarantee!*

We’ll even suggest a worry-free membership plan. This can help you catch AC issues, like water leaks, faster so you can avoid future breakdowns while keeping your house cool.

Contact us at to schedule your air conditioning appointment in North America today!