How Much Water Should Be In An AC Drip Pan? You’ll Be Surprised!

Even if you’ve had an air conditioner for years, you still don’t really know every single part of it, do you? You are not alone! Most air conditioner owners have never seen the internal structure of the air conditioner, let alone the normal state of each part, including the drip pan.

Don’t be alarmed if you notice some water in your air conditioner drip pan. It is normal for water to flow through it. If you’re wondering how much water should be in it, the answer is as much as it stays within its edges.

This is just a short answer. I will walk you through what the drip pan is, where the water comes from, and why there is too much water in it in the following sections. So let’s get cracking right now!

What is an AC drip pan?

ac drip pan

An AC drip pan (also known as a condensate pan or drain pan) is a metal pan designed to catch water that drips down from the evaporator coil. It is located at the bottom of the evaporator coil.

It is a shallow tray, not a water tank, and will not hold much water. The water that passes through it will then drain outside through a drain pipe.

A drip pan can keep water from overflowing inside your air conditioner, preventing corrosion, leakage, and other water damage.

Is it normal to have water in an AC drip pan?

When the AC unit is running, it is normal to have water in an AC drip pan.

Air conditioners will reduce humidity, along with cooling the air. This is because when the air passes through the evaporator coil, the heat in the air will be absorbed by the refrigerant in the coil.

Meanwhile, the excess water vapor in the air will convert to liquid when the air temperature drops below the dew point. This process is also called condensation.

When more and more water droplets accumulate in the evaporator coil, they will drip down, and the drip pan will catch them.

Beyond that, you can also find water in the AC drip pan when the AC is off. This is because not all the water can flow out of the machine or be evaporated (if you have a portable AC) before the machine is turned off.

However, the stagnant water could be a breeding ground for mold and mildew, making it a place you need to clean and sterilize regularly.

All in all, it is normal to see water in a drip pan, no matter whether the AC is on or off.

How much water should an AC drip pan have?

Honestly, it is hard to give a single clear-cut answer to this question because the size of the drip pan varies a lot. Some central air conditioners even have two drip pans to prevent water damage even further. 

But a general rule of thumb is that the water level shouldn’t exceed the edge of the drain pan.

This is because the overflow can lead to damage to electrical components, leakage, and other problems,  which is the last thing you want to see.

Luckily, most air conditioners these days come with a float switch, which can turn off the machine automatically when it detects the water is full.

Nevertheless, an AC drip pan that is full of water is a signal that something is wrong.

What to do if your AC drip pan has too much water?

Nine out of ten times, the drain line is clogged when the water in the drip pan is too much.

If the water gets into the drain pipe but can’t flow out continuously, it will back up and accumulate in the pan. 

The organic gunk or slime in the tube is the culprit, and as long as these substances are removed, you can put an end to this problem. Fortunately, it is not rocket science. Pouring some bleach or vinegar through the pipe can dissolve the buildup and ward off future growth. 

Of course, other factors could be at play, such as a faulty condensate pump, a frozen evaporator coil, or improper installation. You can fix it by replacing the faulty part or thoroughly cleaning your machine. An HVAC expert is always helpful.

Check out more details about why your AC drip pan is overflowing here.

Why is my AC drip pan dripping when it is not full?

Occasionally, your AC can get cracked, allowing water to leak out from the small holes. In this case, the drip pan is the culprit of the leaking issue, but it is not because it is overflowing. 

As your appliance ages, the drip pan inside could start to leak. If you are able to locate the leaks, you can fix this problem by plugging them. Otherwise, replacing it with a new tray is your best bet. Usually, the cost of a drip pan ranges from $20 to $150.

Regular maintenance is required because an HVAC specialist can detect this problem early on, saving you money on repairing a water-damaged AC.

Wrapping up

We don’t know how many gallons of water should be in an AC drip pan exactly, but you shouldn’t be too concerned as long as it is not full of water. 

The drip pan, as a component for collecting condensate, is critical for preventing water damage inside your AC. The water that has accumulated in the pan will then drain through the drain pipe. It’s similar to a transfer station.

As a result, there should be some water in the pan, but not too much.

When you notice the drain pan dripping, pay attention and pinpoint the problem. A crack pan could be to blame, but there are numerous other possibilities.

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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