What Do Drain Holes on a Window AC Unit Do?

South End Plumbing, Heating, & Air Expert Tips

What Do Drain Holes on a Window AC Unit Do

We just expect air conditioning units or systems to work. Most of us, most of the time, don’t care how or why. With a window AC unit, it fits where it’s supposed to and blasts cool air where you need it. There are parts and maintenance to them, though. For example, what do drain holes on a window AC do? There are a few important things to know about drain holes to keep the AC running. There’s some maintenance you can easily take care of and some signs which might tell you something’s off.

What Do Drain Holes Do?

At the most basic level, drain holes in a window AC let the machine keep running while draining water at the same time. Without a way to drain water, the unit would shut off often and there might have to be a manual way to remove excess water or moisture.

An AC system, of any type, cools air drawn in from outside with an evaporator coil. With the temperature change from warm to cool, it causes condensation, and the moisture must go somewhere. It shouldn’t stay in the unit. It shouldn’t leak into the house or anywhere else which would be a danger or a mess.

The condensed water runs out of the drain holes. This lets the AC run while water is removed at the same time.

If you take down a window AC sometime in the fall or winter, you might get a little water dripping, hopefully, no more than that. This is the moisture that was just created and hasn’t run to the drain yet. If you’d rather not get this, turn the AC off and let it sit for at least a day before taking it down.

Drain Pans, Slinger Rings

As a window air conditioner puts out cool air, it’s also dehumidifying the cooler air. The machine probably has a drain pan that holds some water. Then there’s a drain hole or some other piece or mode of draining water from the pan to keep it from overflowing or having standing water grow nasty in it.

Some units have a slinger ring as the main way to remove water. These units have drain holes, too, but they are normally plugged in. The slinger ring normally drains water during typical use. You can unplug the hole or holes if the slinger ring isn’t draining properly or if you need to move or take down the unit and need to drain all of the water immediately.

Where Are the Drain Holes?

Drain holes in a window AC unit are on the outdoor part of the unit. The water should drain outside.

Some newer ACs have a drain pan that will hold some water. This lets the unit be a little more efficient as it can use this water to stay cooler longer. Older window ACs drain the water quicker, through drain holes in the exterior, bottom part of the machine.

In most cases, older units tend to have smaller drain holes and are more likely to clog or become dirty. In newer units, the drain holes are larger, depending on the size of the unit, and less moisture runs out to drain at one time, so clogs are less frequent.

How to Check and Fix Drain Holes

There are some maintenance tips to keep in mind with a window AC unit and the unit’s drain holes. If the AC seems inefficient or worse, broken, here are some suggestions you can check on your own.

  • Turn it Off

This is a fairly simple idea. Turn the AC off. See if it’ll drain on its own for a few minutes. This is pretty common with older window units. Turn it off and let the excess water run out, then turn it on again.

  • Helping it Drain

You may be able to AC drain water out by giving it a tilt. First, this might be a two-person job depending on the weight of the unit, the window, and the need to stay safe.

You can open the window, hold onto the machine, and carefully tilt it down toward the outside, again, carefully. This should help move the water toward the holes.

  • Check for Clogs

Drain holes, especially over months or years, can become dirty and clogged. If you find this, use a pipe cleaner, a coat hanger, a drain snake, or anything to remove the mess. Clean it until the water runs easily again.

What if the Drain won’t Drain?

If nothing’s draining out of the drain hole, or however the water should drain out of the unit, it can cause damage to the unit, a mess in or on your house, or even a safety hazard.

Parts in a window AC can rust and corrode. A clogged drain hole or overflowing drain pan can lead to the unit being backed up and leaking water on the interior side, of your house. The standing water can cause health or safety problems, or just a gross mess near a window.

A Window AC Unit with no Drain Hole

Some window ACs don’t have drain holes, or its plugged when the unit is running. A unit with no open drain hole has a slinger ring. A slinger slings water back into the coils so the reused water is part of the cooling process again. The cooler water keeps the unit as a whole cooler. It’s meant to be more efficient.

If the AC unit has plugged drain holes, they should be left that way. If you need to unplug the holes, turn the machine off first. Then you can check the slinger ring and the drain pan.

At South End Heating and Air we specialize in HVAC and furnace repair, call us for a free consult. We’ll evaluate your system and help make recommendations for optimum value. After all, we want to keep you cool all summer long and warm in the winter. Just schedule a visit with one of our technicians to talk about how we can help with your heating needs. Would you like to learn more options our techs can help you with? Give us a call 704-684-5339.

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