Why Is My Window AC Not Dripping Water? [5 Causes & Solutions]

Anyone who understands how air conditioners work knows these appliances will collect water when in use. That’s why many people are alarmed when they notice their window air conditioners are not dripping water.

If you run into the same issue, this post may help you out. I have summarized 5 common causes of a window AC that does not drip water. Most of them are easy things you can fix yourself, and some of them even don’t require a fix at all. 

Ready? Let’s dive right in!

1. Not all window air conditioners drip water

If you recently purchased a new window unit and discovered that it is not dripping water when turned on, consult your owner’s manual to determine which type of window AC it is. Chances are your model is designed not to drip. 

If this is the case, either there is no drain hole beneath the exterior part or it has been plugged. As a result, no water will come out of your machine. 

You might be wondering where this condensate goes.

I won’t bore you with too many technical details, but in a nutshell, the collected water in the drip pan is used to cool the condenser via a slinger ring around the fan’s circumference. The water will be distributed by the slinger ring as the fan moves.

This lowers the internal temperature and increases the efficiency of your window AC.

What to do?

This is a feature of your model, and nothing needs to be fixed. 

2. Indoor humidity is too low

Window air conditioners, like other types of air conditioners, can remove humidity from the air. However, as the indoor humidity decreases, its ability to remove moisture decreases.

When the indoor humidity falls to a certain level, the condensate will become so little that it only collects in the drip pan and does not drain out through the drain hole or drain pipe.

What to do?

Take a look at the humidistat in the room. You don’t need to do anything with your air conditioning unit if the humidity level is low.

3. Drain hole or drain hose is clogged 

If you have a window air conditioner that previously drained water but has recently stopped, the drain hole or drain hose is most likely blocked.

This is a common issue in older units because more and more buildup and slime can become stuck in the hole or hose, preventing water from draining.

What to do?

You can use a soft cloth to take away the buildups around the drain hole. If you use a drain hose to drain water, you can remove it, use a wire brush to dislodge the buildups, and then pour some bleach or vinegar through it to ward off future growth of this gunk. 

4. Your window AC is tilted forward

A window unit is usually slightly tilted backward to help condensate flow to the back of the cabin and then down to the drain hole.

When it is tilted forward, for example, due to improper installation, the condensate pan overflows, but the water collects in the front of the cabinet or even leaks on the floor or window frame.

What to do?

Cut off the power and then try to adjust the entire unit slowly, making sure it is tilted backward. 

5. Frozen evaporator coil

When your window AC is freezing up, it will not drain water immediately since the moisture has turned to ice. But you will notice a significant amount of water coming out of the drainage hole later on when the ice starts to thaw. 

What to do?

Many reasons can cause a window AC to freeze, including a dirty air filter, refrigerant leak, or a filthy coil. Therefore, you should first pinpoint the problem and then find a way to resolve it. 

For example, nine times out of ten, the culprit is the dirty filter. You need to remove it, wash it, and then reinsert it.

If it is caused by a low refrigerant level, you should call for an HVAC professional due to the fact that refrigerant is hazardous, and you are not permitted to recharge it yourself. 

In conclusion 

Hopefully, this post has helped you to figure out why your window ac is not draining water. 

If you have a new unit, the cause could be that it is a “no drain window ac,” which is more efficient than older models. An incorrect installation could also be to blame.

If the model has served you well for many years, inspect the drainage hose and hole. It could be clogged.

Besides, it can occasionally be caused by excessively dry indoor air.

If none of these are the culprits, check to see if the evaporator is frozen and look for solutions.

About The Author

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Liz Yang is the founder of Airsmartly. She has been working at home for a few years and realizes that the performance of the HVAC system plays such an important role in our life. She has tested dozens of products in person, like humidifiers, air purifiers, dehumidifiers, and ACs, and wants to share tips about using or troubleshooting these products with you. Her uncle is an HVAC expert with over 30 years of experience in the field, and often offers assistance when she is unsure how to handle a situation. He is also in charge of reviewing the articles on this site.

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