COVID-19 Update:

We are open to safely serve you during this time. Click Here to read more about our increased safety precautions.

How Does a Condensate Drain Pan Work?

How Does a Condensate Drain Pan Work?
Why Is the Air Conditioner Leaking Water?
September 18, 2017
How Does a Condensate Drain Pan Work?
Good Deeds Even On His Lunch Break!
September 19, 2017
Show all

How Does a Condensate Drain Pan Work?

How Does a Condensate Drain Pan Work?

Condensate Drain Pan Work


The condensate drain pan is an important part of the entire central air system. It protects the home against water damage. It protects the furnace from microbiological growth and failure. Most importantly, it protects the home from any type of water-related safety issues.

Condensate Drip Pan 600 - How Does a Condensate Drain Pan Work?

Condensate Drain Pan

Homeowners interested in keeping their home and air healthy and clean should also care for their condensate drain pans.

How does a condensate drain pan work?

The primary purpose of the condensate drain pan is to collect water that results from the air conditioning process. From where does this water come?

Whenever the thermostat is turned on for air conditioning, the evaporator coils of the central air system fill with compressed refrigerant. These A-shaped coils drop to very low temperatures, growing cold.

Evaporative Coil - How Does a Condensate Drain Pan Work?

Warm moist air from inside the home enters from the air ducts. It then passes through the air filter and through the open center of the evaporator coils. This is where a heat transfer takes place. Moisture and heat is pulled from the air. Cooled air is then pushed through the air ducts and into the house.

As this process repeats, water results from the heat transfer. It’s similar to a glass of ice water on a hot day. After just a moment, the glass is covered in beads of water. In the same way, tiny water droplets collect. Water slips down the sides of the evaporator coils and right into the condensate pan fitted below.

This process continues until the air conditioning is turned off. To safely remove excess water, the condensate drain pan is installed to catch water that drips off the evaporator coils. Then, from the pan a condensate line moves water out of the home, emptying to the sewage system or another external location.

Where is the condensate drain pan located?

A condensate drain pan is part of the evaporator coils. The evaporator coils is a box of coils that sits around the furnace. Its exact location depends on the type of furnace installation in your home.

  • Vertical furnace installation or application

Vertical furnace installations are in the upright position. Typically, the furnace is installed in the furnace closet or garage. With these furnaces, the evaporator coils sit on top of the furnace. The condensate drain line is right beneath the evaporator coils.

  • Horizontal furnace installation or application

Horizontal furnace installations have the central air system lie on its side. The furnace is installed in the attic and placed in this position because of space constraints in the attic. Air flows side to side rather than up and down. The evaporator coils sit beside the furnace with the air ducts in the attic.

Why does the horizontal application have a second drain pan?

Backup Drain Pan - How Does a Condensate Drain Pan Work?

Backup Drain Pan

For furnaces in the attic, there is a second condensate drain pan. This is in place as an added layer of protection against water damage.

Because entire central air system is lying on its side, in the event of condensate drain pan failure, water does not drip in one general location. Instead, water drips from the entire central air system. In addition, overflow of water results in damage to the ceiling drywall and wood. In order to protect the home from water damage, a secondary condensate drain pan is fitted beneath the entire central air system. This is similar to placing a pan beneath the car during an oil change. The added barrier protects the floor from stains and other damages.

This secondary condensate drain pan also has its own drain line. It is connected directly from the pan to an external location, usually traveling out the window. It is highly visible. Homeowners should notice when the central air system reverts to this water removal method. It means that the standard method has been compromised. An HVAC specialist should be called in order to make timely repairs.

How does the condensate drain pan get damaged?

Unfortunately, the condensate drain pan can fail.

In the past, condensate drain pans were built of metal. Then, HVAC specialists discovered that water created rust that ate at the metal creating holes and leaks. Since then, condensate drain pans have been made of plastic.

These plastic condensate drain pans are durable, lasting between five to 10 years. However, they are a part of the evaporator coil system and cannot be replaced independently.

What damages the condensate drain pan?

The condensate drain pan is meant to collect water that results from the air conditioning process. When homeowners do not use air conditioning, they opt for heating in the colder months. Because the condensate drain pan is located right by the furnace, either on top of below, it is in the path of hot air with each heating cycle. The constant batter of heat sucks out the moisture of these plastic pans. Eventually, it leads to cracks.

A cracked pan is unable to hold water. When homeowners return to air conditioning, water slips through the cracks of the pan, either pooling at the bottom or trickling throughout the furnace interior.

In addition, the drain itself can clog. This can result from a dirty air filter, foreign obstruction or simply old age. In this instance, water never makes it through the condensate drain line. Instead, water backups and fills the condensate drain pan. Unfortunately, these pans are not designed to carry large amounts of water. They’re quite shallow, and built to hold water for a short amount of time as water should empty through the condensate line. In the event of an overflow from a clog, water drips backward toward the furnace.

A clogged condensate line, a cracked condensate drain pan or a soggy furnace can lead to many unwanted issues. This includes:

  • Microbiological growth
  • Safety hazards
  • Low indoor air quality
  • Internal buildup
  • AC repairs
  • Higher energy expenditure
  • Smelly air
  • Water damage to the home

Homeowners who find water pooling anywhere around their central air system should contact their HVAC specialist. Quickly finding repairs saves time, money and trouble that could avoid more permanent and serious damages.

Care for Your Condensate Drain Pans with Service Champions Experts

Service Champions Heating & Air Conditioning is the only Diamond Certified HVAC provider for Orange and Los Angeles Counties. Our technicians lead in superior technical care for furnaces and air conditioners.

Homeowners of Southern California rely on our expertise and experience for exceptional HVAC service and genuine customer care. Your satisfaction is guaranteed.

For the best in home comfort and peace of mind, rely on Service Champions. Complete the form below or speak to a friendly call center representative for further assistance.

Schedule Service

Comments are closed.