Is Your AC Leaking Water?
Updated: Mar 18
Before you do anything else, turn your unit off as the water can cause damage to electrical parts, wiring, and your home. If you don’t feel comfortable trying to diagnose the leak yourself, call an HVAC professional to find out why your AC is leaking water.
1. Blocked or Rusted Drain Line
Your AC unit has a drain tube to drain accumulated water and it can get clogged up. If the drain line has been blocked, the water is not able to escape and backs up into your home. Things such as dirt, insects, fungus, mold, or anything small can cause a blockage. In some cases, there may be a second drain line that can also become blocked.
Examine the tube to see if it’s rusted or any debris is blocking the hole at the end of the line. If there is, you need to clear it. You can use a wet-dry vacuum to remove the blockage from the outside condensate PVC pipe or you can use a product called the Mighty Pump, a small hand pump that can free any blockages, is a popular option and can be purchased online.
Another culprit for a clogged drain could be a dirty evaporator coil. This happens when the water from the coil carries dirt into the pan and causes the drain to clog. We recommend having the coil cleaned at least annually by a professional, as part of the yearly AC maintenance.
2. Broken Condenser Pump
Water leakage can also be caused by a broken or malfunctioning condenser pump. To test the condenser pump, you can pour water into the condenser pan, if it is working properly, the excess should be pumped out. If it’s not able to pump the excess out, check to make sure the pump is getting power. If it gets power, then it’s probably the motor or condenser. A professional should be contacted to determine the exact issue and correct it.
3. AC Unit Installed Incorrectly
AC Units can also leak when they have been installed incorrectly. If it is installed, but not level, water will leak. Start by checking if the unit is level. If it is level, then look for closed vents around your house as this can cause added pressure on your AC unit and also cause leaks. A condensate trap that was improperly designed can prevent drainage as well, causing water to build up and overflow. A professional can examine the trap to make sure it is correctly designed and installed.
4. Cold Weather Temperatures Outside
When it starts to get too cold out, this change can cause excess water. More water means it will collect and overflow and because it’s not as hot out, it will take longer to evaporate and dry up. If the pooling of water is small, it may be normal and not require anything but a warmer temperature.
5. The AC Seals are Bad
If the AC unit has seals that are not properly fitted anymore, whether due to aging or just becoming loose, it can allow too much hot air to enter the unit. When the warm air hits the cold air in the unit, it condenses moisture and creates excess water to collect under the unit. By resealing the unit, this can be corrected.
In the situation of damaged or loose seals, the extra warm air entering the unit creates moisture and a pool of water under the unit. Resealing the outdoor unit can correct this and make things close properly, but water leakage is not the only problem that can arise. It is important to take care of the seals because it can reduce the efficiency of the unit, meaning you are not getting the temperature indoors that you desire and it may be costing you more money. If you are unsure of how or where to examine the seals, please call an HVAC professional.
6. Air Filters Get Dirty
One of the most neglected aspects of the AC unit is the air filters. When they get clogged, it causes the airflow to become blocked, and not as much air can hit the evaporator coil. This causes the coil to become too cold and causes it to freeze up with ice. As the ice melts, the excess waterfalls in the drain pan, which may not be designed to hold that much water. The first thing you should do if the unit is freezing up is to check your filter. If it’s dirty, clean it (for reusable filters only) or replace it with a new one. Depending on the season, it’s recommended to change or clean your filter every 1-3 months.
7. Ice on Your Evaporator Coils
To determine if your evaporator coil is freezing over, open the blower door located inside the AC Unit. Can you see the ice? If so, the water could be caused by the melting of this ice and the drainage pan is overflowing.
When it comes to ice on the evaporator coil, there are two primary causes:
Dirty air filter – When the filter is dirty, it reduces the warm airflow access to the coil and causes it to get too cold and freeze. Change or clean the filter.
Low on refrigerant – When the refrigerant level is too low, it can cause the evaporator coil to become too cold and freeze.
Things that can reduce or prevent AC water leakage:
Ensure that the central AC system is using a secondary drain line, particularly if the unit is in the attic.
Have drain pan shut off switch with float installed
Make sure the AC unit has a safety pan to catch the overflow.
Regularly clean or replace HVAC filter
Regularly check AC refrigerant levels
Use a 50/50 solution of water and bleach to prevent mold or mildew build-up in the condensate pump.
Make sure drain lines include an air vent and p-trap.
Make sure AC seals are not damaged or loose.
Schedule yearly HVAC maintenance to ensure the best performance
If you are still unable to determine the cause for your leaking water or have found the cause and need maintenance or repairs, contact 3HAC today. Don’t wait for AC or water damage to occur or get worse. 3HAC serves Tampa Bay and surrounding areas with a 24hr response time.