Why Is AC Spitting Water Inside, Making Noise? (2 Reasons)

Air conditioner spitting water. This is quite a common problem in hot and humid summers. The water that is coming from the air conditioner is not merely leaking; you will see air conditioner water spray inside the house. Let’s explain what is happening when AC is spitting water into a room, and how you can fix it (it’s really easy).

why is my air conditioner spitting water inside the room
When running an AC unit, the water should flow outdoors. If it starts spitting water inside the room, something is not right with the drainage.

Here’s why we decided to address the whole portable or window air conditioner spitting water problem:

We get a lot of questions regarding “Why is my air conditioning spitting out water”. Example: In our article about the causes and fixes for window air conditioner leaking inside here, we have received this comment that illustrates pretty well how you can fix a spitting AC unit:

how to fix an air conditioner spitting water (1)

Mind you, this is not just an air conditioner leaking water. It is literally spraying it inside your room. Predominantly, we see two types of AC units having this problem, namely:

  • Portable air conditioner spitting water into the room. This can be any portable AC brand; Haier, LG, and so on.
  • Window air conditioner spitting water inside (on the side facing your room).

We are going to explain why this water spraying happens and how you can fix an AC unit that is spitting water (DIY fix).

Note: Fixes you will mostly find on the internet like damaged drain pan, dirty filters, even refrigerant leak will be useful if your air conditioner is leaking water.

We are not talking about leaking here; this is an AC unit spitting water quite violently.

As we will see further on (obvious from the comment as well), dirty air filters don’t make AC spit water. Neither do low refrigerant lines or damaged drain pain. There are only 2 things that will make an air conditioner spit water indoors:

  • Clogged condensation pipe (in more than 80% of cases).
  • Im-properly tilted window air conditioner.
window ac unit spitting water and making water noises
If the water in the drainage is not adequately removed, the water levels inside the drainage pan will reach the AC fan blades. Fan blades smashing into the water will make the window AC unit spit out water and make noises.

Here’s a quick summary:

  • AC is spitting water due to a combination of high temperatures + high humidity levels + inadequate or obstructed draining.
  • You can fix an AC unit spitting water by ensuring smooth draining. There are only 2 things that will cause an air conditioner to spit out water: a clogged drain pipe and an unproperly tilted window air conditioner. Basically, the high temperatures + high humidity levels are the reality and we can do nothing about that; but we can prevent the water inside the AC unit to accumulate too much with proper drainage.

Let’s look at exactly what is happening when your AC starts spitting water:

Why Is Your Air Conditioner Spitting Out Water?

Here is how air conditioners remove water from your indoor air (reduce moisture):

  • Hot and humid indoor air is sucked into the air conditioner.
  • Inside the AC, the air is passed over cold condensation coils (usually made out of copper). These coils will cool the air. At the same time, excess air moisture will be condensed on the cold coils. This is much the same phenomenon when we see air droplets condensated on a cold window.
    too much water inside air conditioner
    Air moisture is condensed on the cold coils. The same thing happens when air moisture is condensed on cold windows.
  • From the condensation coils, the water will most usually drip to the condensation drain.
  • From the condensation drain, if everything is OK with drainage, the accumulated water will be leaked outside.

Now, as you might imagine, if your air conditioner is spitting out water, something in this process might go wrong. As a result, the water will be continuously accumulated in the drain pan.

When the water levels are too high, we will see the air conditioner spitting water and making noise. That noise that we hear is fan blades hitting the accumulated water inside the AC unit.

Essentially, AC water spitting occurs when the AC fan blades start hitting the water. Why? Well, because water can’t be effectively drained.

There are only two reasons why this might happen:

Clogged Drainage Pipe (Especially Partially Blocked On Humid Days)

The water levels in the AC should never be so high that they could reach the fan, of course. As noted before, in most cases, the problem is that:

  • Drainage pipe is completely blocked. This will make your AC spit water in any weather (you don’t need high humidity or high temperatures).
  • Drainage pipe is partially blocked. This is mostly the case. The water is being drained but not at 100% effectiveness because there is dirt, dust, leaf, and even mold partially blocking the pipe. During normal weather, the partially blocked pipe might still be able to remove excess water (we might see slight leakage indoors). We will see AC spitting water on high humidity and high-temperature days; when you have so much air moisture, that partial water removal will be overwhelmed. As a consequence, the water levels inside the air conditioner will rise up to the fan blades, and you will see AC spitting that water inside.

How to fix a clogged drainage pipe: Just unclog it. That is not all that easy.

Here is how you do that:

  1. Located the drainage pan. It’s usually located on the bottom of window and portable air conditioners.
  2. Flip the AC unit to remove the panel securing the drain.
  3. When you are looking at the drain pain, look for a small hole (about 1/2 inch in diameter): that’s the drainage hole and can be connected to a hose. If you have a clogged drain, you will see that there is dirt inside that hole.
  4. Remove the dirt. You can use a small toothbrush, pipe cleaner, or even a toothpick. Just make sure to remove all the dirt.
  5. Reassembled the AC unit.

When you have cleaned the drainage hole and pipe, the water will be adequately drained again. You won’t see water build-up inside the AC unit and, hence, the air conditioner will stop spitting the water inside (because the fan blades can’t reach it).

In addition to clogged drainage, unproperly tilted window AC might also be a problem causing the window AC to spit water out (it might even be a combination of a partially clogged drain and tilted AC):

Unproperly Tilted Window Air Conditioner (Just Balance It)

A window air conditioner should be leveled on the window sill. You might also want to tilt the window AC outward as described here.

Here is why a tilted window AC is spitting water:

Imagine that the drainage works alright. However, the window AC is tilted inwards too much. That means that the water will start accumulating inside the part of the pan that is lowest.

A drain hole is usually located on the outward side of the window AC unit. If the unit is tilted inward, the accumulated water just doesn’t reach the drainage hole. As a result, the water levels will continue to rise and they might match the level where the fan blades are spinning.

Needless to say, when the fan blades start slashing in that accumulated water, you will notice your window air conditioner spitting water and making noise.

How to fix an improperly balanced window AC unit: Just balance it; it needs to be leveled with the window sill. You may want to slightly tilt it outwards at a very small angle, as well.

When you do that, the accumulated water will have access to the drainage hole and pipe, and the water will leak out outdoors, preventing the amassment of water that cause the window AC to start spitting water.


All in all, it is not that uncommon to see enough water accumulation that makes the air conditioner spit water. It’s fairly easy to solve this noisy and spitting air conditioner. You just have to:

  • Clear the drainage hole and pipe.
  • Balance the AC unit or tilt it slightly outwards.

We hope that this illustrates well why is your air conditioner spitting out water. Understanding the causes will also help you prevent the AC from spitting water indoors in the future.

Leave a Comment