It is common for people to pick up the phone and call a professional if they notice that their Window AC water leakage. It is totally normal and to be expected that your AC unit will produce some condensation under certain circumstances. When it is very hot and humid outside and the thermostat setting is low, the unit will produce some condensation because it is working very hard to cool your house.

It's best to call an HVAC repair company to inspect your AC unit if you have questions about condensation or leaking. Generally, your AC unit should only produce condensation when it is running. It should dry up within a day or two.

You should be concerned if your air conditioner leaks lots of water inside your home. The first thing you should do is turn off your air conditioner and call a professional. If you don't act quickly, water damage may cause even more damage to your home and lead to expensive repair bills. Any of the following problems could result in a leaky AC unit.

Leaking Air Conditioners: What Causes Them?

• The condensation drain is blocked. It is very common for a blocked condensation pipe to cause a window AC to leak water. Condensation is drained from the overflow pan to the drainpipe through the condensation pipe. If this line is clogged with dirt, dust, sludge, or mold, water will back up and flood. In some AC units, the condensation drain automatically shuts off if there is an overflow, so if you have an older AC model, you are at risk for a blocked drain.
• Condensate pan damaged. It's possible that an older AC unit's drain pan is rusted or corroded and leaking water. A condensate pan is typically located under an air conditioner and is easy to check yourself. Take a flashlight and inspect it for corrosion, holes, or cracks.
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• Filters that are dirty. When air filters become too dirty, they can block airflow over the evaporator coil, causing it to get too cold and freeze. It can drip excess water into the pan when it melts, causing your Window AC water leakage  when it floods. Regularly changing your air filter is always a good idea. It is recommended to check it more frequently, every couple of weeks, during the summer months.
• Refrigerant levels are low. As with dirty air filters, low refrigerant levels will also lower the overall pressure in the AC unit and cause the evaporator coil to freeze. As a result, excess water overflows the drain pan, causing flooding, which can result in your window AC leaking water. Low refrigerant levels can sometimes be repaired, but in many cases, it means your whole unit needs to be replaced.
• Pump for condensate is broken. A condensate pump will channel the water outside for homeowners with an AC or furnace in the basement. Damaged or improperly installed pumps can cause your AC unit to leak. In this case, it will need to be repaired or replaced.
• An improper installation. In the event that you just had a brand new AC unit installed and you're already experiencing leaks, it's likely the unit was improperly installed or too small or too big for your home. A technician can assist you in assessing the situation.