The moment you discover water dripping from your air conditioning unit—which can result in water damage to your house—take the immediate step of shutting off your air conditioner. Because the water might be affecting the electrical components in a harmful way. The next step is to call in an air conditioning repair professional to take care of the problem.

If you’re curious-minded about how the problem of the central air conditioner leaking water inside your home occurs, read on for a basic explanation about how water is created during the operation of your air conditioner, and why water from the air conditioning ends up on your floor.

What Causes Condensation on Your Air Conditioning

Among the many functions your air conditioner performs, one of them is the evaporation of humidity from the air inside your home. First the air conditioning blower draws hot and moist air through the return grille and sends it to the air conditioning evaporator coil for cooling. The evaporator coil forms condensation in the appearance of droplets much like you find on a cold beverage during hot weather.

The water from the evaporator coil then spills into a slanted drain pan, and further into a condensate drain line, exiting either into your plumbing or outside your home. If the condensate drain line, drain pan, or evaporator coil is malfunctioning standing water is the result.

There are 7 common reasons which often cause the A / C unit leaking water on the floor:

  • Condensate Drain Line

A blocked drain line which is filled with debris such as dirt, mold, insects or other matter forces the water to back up into the house.

  • Evaporator Coil

A grimy evaporator coil causes the mixture of dirt and water, which seeps into the drain pan, causing it to become plugged up. If the drain pan has become corroded with rust, enough to allow water leakage to occur, that also causes the A / C unit leaking water on the floor.

A secondary problem with the evaporator coil is when it freezes over. As the frozen water melts, and there is a lot of it, it streams heavily above the drain pan, and water dripping from the air conditioning unit results. How does an evaporator coil become frozen? Most often either it’s a grimy air filter, or low refrigerant.

  • Air Filter

An air filter, which has accumulated debris of one kind or another, becomes blocked and prevents airflow from traveling above the evaporator coil. This results in a temperature drop to below freezing, causing the evaporator coil to ice over.

  • Refrigerant

If there is not enough refrigerant the evaporator coil will also freeze over.

  • Condensate Line

A blocked condensate line is the number one reason for A / C leaking water inside the house.

The condensate line receives condensation from the drain pan and sends it into a drainpipe or outside the home. A blocked line causes water backup, flooding the overflow pan.

How to Unclog an A / C Drain Line

If you own a current-model air conditioner it may feature a water-overflow shutoff lever. When your air conditioning unit senses a blocked condensate line, it will move to automatically shut off the air conditioner, to aid in preventing water damage. Check the condensate line and clean it if it is dirty.  An

a / c drain line cleaning tool such as a wet / dry vacuum can be used to clear the blockage.

But it’s better to be proactive, and avoid a blocked condensate line altogether. You’ll avert water damage and save on costly service calls. Make it a habit to unclog the air conditioner drain line with bleach. After clearing the blockage, use chlorine bleach by pouring it into the line. Do this two to three times a year.

  • Installation

If you own a modern air conditioner, the installation of it may be at fault. This could mean a poorly-designed condensate trap has stopped the condensate from draining. The drain pan fills with water and floods your home, causing the air conditioner to drip water inside the house.

Another installation issue is a disconnected drain line. This occurs when an air conditioning technician hasn’t had enough experience installing air conditioners and doesn’t attach the drain line correctly. A loosened drain line can result in a water leak.

  • Insulation

Insulated coils perform the function of allowing built-up condensation to flow down the coil. If the insulation develops fissures or holes, water will drip rather than flow, causing the A / C unit leaking water on the floor, with the potential of water damage if you don’t discover the problem soon enough.