why-is-my-air-conditioning-unit-leaking-water.jpg Are you thinking, "Why is my air conditioning unit leaking water?"

To start, it’s important to understand why your
air conditioning unit has water in it in the first place.

The air conditioner contains an evaporator coil that cools the warm air that’s blown over it. This causes condensation or moisture to form on the evaporator coil. It’s similar to how water droplets form on a cold glass of water on a hot day.

The moisture on the evaporator coil drips into a drain or drip pan and down a condensate drain line, which is a white PVC pipe, that leads out of your home.

So, what causes this water to leak into your home?

The condensate drain is clogged. This is the most common cause of water leaking from your air conditioning unit. If the condensate drain is clogged with dust, dirt, mold, or other debris, water can back up into your home. To fix this, call an HVAC technician to use a special vacuum to suck the blockage out.

The drain pan is rusted or damaged. Most air conditioning units last between 12 and 15 years. If your unit is around this age, its drain pan may be naturally rusted or damaged. You should replace the pan as soon as possible.

The condensate pump is broken. If your furnace and/or indoor A/C unit was installed in the basement, you can find a condensate pump that pumps water outside. If it breaks, water isn’t being pumped outside anymore. Call an HVAC professional to repair or replace the pump before you have a flood on your hands.

The air filter is dirty. A dirty air filter blocks airflow over the evaporator coil. When that happens, the evaporator coil gets too cold and freezes over. When it melts, it drips an excess amount of water that the condensate pan may not be able to handle.

Check your home's air filter to see if it’s dirty and change it if needed. It should be changed monthly (or more frequently depending on the season and how dirty your indoor air quality is).

The refrigerant is low. Low refrigerant reduces the pressure in the A/C system, causing the evaporator coil to freeze over. Like we mentioned before, when the coil melts, water overflows the drain pan.

You’ll notice you’re low on refrigerant when the air conditioner isn’t cooling your home well or you hear hissing or bubbling. Depending on the severity of the refrigerant leak, you have to call an HVAC technician to repair the leak or replace the entire unit.

The unit was installed incorrectly. If you have a new air conditioner with a leak, the problem may be installation related. An improperly designed drain pan will stop the condensate from draining, leaving water to build-up in the drain pan and overflow into your home. Call a professional to inspect the installation and make repairs as necessary.

Condensate buildup is in un-insulated ductwork. It takes a professional to identify this air conditioning problem, but you can avoid it by ensuring your home's ductwork is properly insulated. 

According to Popular Mechanics, “nearly 90 percent of all central-air service calls are related to [air conditioner] leaks.”

Usually, it’s one of these common air conditioning problems. If you’re lucky, your unit has a secondary drain pan to catch the water. This pan has a float switch that turns off your air conditioner to prevent water damage.

If you’re not so prepared, feel free to call your local HVAC professional to fix the problem. You should prep by downloading Warner Service’s HVAC Maintenance Checklist by clicking on the button below:

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