Central Air Units Condensate Drain Pan N Line
It’s disgusting- Yes, it will be

What is a condensate drain line in central air units?

A condensate drain is just a pipe that removes water from the evaporator coils.

Condensate drain has a:

  • P-Trap
  • Pipe
  • Drain pan
  • Condensate pump

The drain pan or the evaporator pan is located underneath the evaporator coil.

Condensate drain line

Should you install a trap in your condensate drain line?

Yes, installing a p-trap to your condensate drain allows the condensate water to flow freely. Without the p- trap installs, the air handler negative pressure will pull in the positive pressure air, this prevents condensate water from flowing.

Read Homeowners Question and Concerned

Central Ac Unit Condensate Drain Line

There is two or one condensate drain pan in central air units

The number of drain pan in central air units are depending on the location of the air handler unit.

Air handler unit in the ATTIC

When the evaporator coil and drain are located in the attic, it is recommended or required by local code to have two condensate drains.

Condensate drain pan

The first drain pan is the known as primary drain pan and the secondary drain pan is known as the auxiliary drain pan.

Primary drain pan

The primary drain pan is within the air handler; it is underneath the evaporator coil.

Auxiliary drain pan

The secondary drain pan is located beneath the air handler; it is not within the close compartment.

It purposes is to tell you the first primary drain pan is clog and you need to fix it. It will be drain in a place that is visual; it is a sign of warning to the homeowner.

When an air handler in the basement; it does not required to have an auxiliary drain pan. Where is the condensate drain line on the furnace?

A package unit on top of the roof needs to be drain purposely if it is outside; it is not a big deal. In split central air conditioner, the drain line is in the basement or in the attic.

Look for a tube that travels from the air handler to outside. The tube could be white colored PVC pipe with P-trap. Some air handler unit will have a condensate pump to help move the water if gravity does not apply.

How to install a condensate drain in central air units?

You will need:

  • Coupling
  • PVC tubing
  • P trap

Tools you will need:

  • PVC glue
  • PVC cutter or saw

Condensate Drain Pump in Furnace Unit

Do I need condensate drain pump?

If the condensate needs to pump a drain at higher level, it needs the condensate pump. Condensate pump is useful when gravity is useless.

Condensate pump will have a float to turn the pump on and some pump will have second float and safety switch to turn the central air units off, if the first float fails.

How much water does a central ac unit produce?

Each ton of central air conditioning in a climate with average humidity will produce 48 ounce of liquid (3 pints) per hour of operation.

A 4 ton central air conditioner unit will condense about 64 ounce of liquid (12 pints) per hour of operation. The evaporator is removing more than a gallon of moisture per hour.

Here is another way to determine how much water your central air units are producing, place a measurable container underneath the condensate outlet of your furnace and see how much it fill the container.

Should I drink the condensate water?

You should not drink the condensate water; however, it is useful for your garden or grass.

What causes condensate water to leak?

Leaks will occur when the evaporator coil drain line becomes clog. Some central air unit will not have float switch at the pan to tell the central ac unit when the evaporator pan overflow with condensate water. That is when the leak becomes visual.

Clogs condensate line can be caused by attic insulator, insect and airborne particle, such a pollen and dust. Algae build up in the lines, trap, and pans will clog the drain line.

Drain pan can fails – overprotects it by

Air handler does have secondary drain pan to protect the sheetrock. The primary and secondary drain line could clog and it will cause mess. The best solution is to install drain pan switch to turn off the condenser unit, whenever the secondary pan water level rises.

It low voltage and expensive safety switch connection. The drain pan switch will be wire through the condenser unit. Ask hvac technicians to install it, if you have air handler in the attic.

Condensate drain line needs maintenance

The drain line needs periodic flushing to prevent algae build up and other growth substance. The Ac maintenance should be done by you or by your service HVAC company during annual maintenance or system tune up.

If you evaporator coil is in the attic, do not put this off. Flushing the drain line is serious work and it need to be done annual or you face financial problem.

You can pour 1/2 cup of bleach into the condensate line once or twice a years. This is the best way to eliminate unwanted sticky material in the drain line.

Video on how to clean central air units condensate drain

Video by JohnCFlood


Return to central air conditioner and refrigeration cycle from central air units