Why Is My AC Drain Pan Full of Water?

As warm weather rolls in and the seasons begin to change, it’s crucial to make sure that your AC is working at its full potential to mitigate any unbearably hot days. While reviewing your AC system ensures you maintain optimal comfort in your home, it’s not uncommon to find that your AC drain pan has some sitting water.

If left unchecked, this issue can result in long-term damage that can lead to significant issues with your unit. In today’s article, we cover some of the main reasons your AC drain pan collects excess water and how to remedy the situation safely.

What is an AC drain pan?

Before we dive into the root cause of the issue, let’s take a moment to understand the fundamentals of your air conditioner system.

An AC drain pan, also known as a condensation pan, is a tray that catches any condensation that falls from the evaporator coil.

How do AC drain pans work?

Within your unit, there are two pans to catch water. The primary pan has a drainage tube to safely remove water from within and around the system. The backup drain pan is the other unit and should only catch water when there’s a clog in the primary pan. The presence of these pans is critical in avoiding prolonged water damage to your home.

Why is it important to have a drain pan?

Without a working condensation pan or backup drip pan, any water that accumulates on the coil and drips off will fall directly within the unit or the surrounding wall or flooring of your house.

When water comes in contact with the electrical circuits, or the wood or drywall enclosing the space, water damage to both the unit and the structure can occur. At best, this may only cause mold and mildew, but at worst, it can debilitate your AC unit or structurally compromise your home, resulting in costly repairs.

Where would you locate the AC drain pan?

Locating both the primary and secondary drip pain can be as simple as removing a panel and assessing your system. The primary drain pan is located directly under the evaporator coils in the center of the unit. You can usually identify this by a drain line. The secondary pan is located at the bottom of your air conditioning unit and should be easy to access.

Causes of full AC drain pans

When it comes to standing water in your drain pan, there are a few potential culprits behind the water issues. Below are a few of the most common reasons why your pan can become full of water:

Undetected damage

Sometimes the simplest answer is the actual answer. If your drain line or drip pan cracks or breaks, the condensation can leak from the primary retention source and collect at the bottom of the unit.

Clogged drain pipe

Clogged drain lines are also common causes for a pan full of water. When the primary outlet for water dispersal gets congested, water can back up and flood the primary pan inside the unit. This causes water to collect in the bottom tray. To address this issue, check to see if your AC unit has a clogged drain pipe.

Frozen coil

A frozen evaporator coil is another common reason for a full water pan. As the frozen coils begin to thaw, the resulting AC drip can fill up the pan's capacity. Freezing usually occurs because of dirty air filters that limit air intake and cause coils to ice up.

How to remove the water safely

Does your tray have water in it? Don’t panic! Here are a few ways to remove the water safely and without making a mess:

Use a shop vacuum

If you have a shop vacuum on hand, this is going to be the best course of action. If you don’t have one on hand, you can soak up the water with towels to avoid any spillage.

Check for blockage in the drainage system

Once you remove the water, search for any blockages preventing drainage. This keeps any future issues from occurring and helps you narrow down what the problem could be.

Contact a professional

If you’re not sure what’s causing the issue in your AC unit, call an HVAC expert! A licensed technician will be able to evaluate your air unit and spot both current and potential issues.

Stellar Cooling Services keeps your home cool and comfortable!

The professionals here at Stellar Cooling are happy to fix any of your air conditioning problems to keep your unit up to date with the appropriate AC maintenance. We know the importance of fighting off oppressive summer heat, so give us a call or contact us online to learn more about how we can help you.