Why Is My Air Conditioner Leaking Water?

Staring at a puddle of water near your AC unit? Yeah, that can cause a bit of anxiety – but rest assured that you are not alone! Almost 90 percent of all air conditioning service calls are related to leaks.

Your AC does not use water to operate, it does however, create a fair amount of condensation which is what you’re staring at.

First, here’s how your AC works:

The job of your AC unit is to pull heat and humidity from the air and use it to condition your home. The system’s blower sucks the air in through an air vent which then works its way through the units cold evaporator coil to condition the air, absorbing the heat.

The more humid the air = the more condensation.

Where does the water go?

The condensation goes into a drain pan then down a condensate drain line, leading the water to a floor drain, condensate pump, or a pipe outside your home.


  1. Clogged Drain Line

This is the most frequent cause of water leakage from an AC system. Your drain line can get clogged by numerous things including dirt, insects, and mold. This could lead to problems such as water damage, electrical issues, and health hazards from mold and bacteria. Call a professional to help unblock your drain line.

  1. Damaged Drain pan

Your AC’s drain pan may be damaged or rusted through causing an overflow of water. If you notice that your drain pan is damaged, you will need to replace the pan.

  1. Condensate Pump Problems

The pump allows the water from the unit to go outside. If it’s malfunctioning or dirty it can lead to serious water leakage that can flood your attic or basement (depending on where your AC unit is located).

  1. Low Freon/Refrigerant

Low refrigerant can cause the evaporator coil to freeze over. Once the coil begins to thaw out, water can overflow the drain pan. If you notice your air conditioner isn’t cooling properly or you hear a hissing noise from your unit, you may be low on refrigerant. You will either need to repair the leak or replace the whole AC unit.

If you notice that your air conditioner is leaking water and you need professional assistance, call the experts at Uptown! We provide fast, quality, same day repairs on air conditioning systems across the Twin Cities – St. Paul area.

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