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Condensate Pump Drain Li

Condensate Pump Drain Line Termination


Richard Acree

Condensate pumps like that shown on the right are frequently used to literally pump the fluid drained from an HVAC evaporator coil to a place where it can be disposed of properly. In the best scenario, a condensate pump is not necessary and the condensation fluid is simply drained to an exterior port of termination. If draining the fluid is not possible, a condensate pump is used to lift (ie. pump) the fluid to an exterior termination point. Conditions that require a condensation pump is when an HVAC split system interior unit, which contains the evaporator coil, is mounted in a basement or garage. In these locations the unit is mounted at one of the lowest positions in the building and perhaps below the exterior grade. In order to properly dispose of the condensation fluid, the fluid must be lifted to an exterior termination point.

So what's the problem? Well, sometimes people can be creative with their condensation pump terminations. Really! The idea is to remove the condensation to an exterior termination point. Sometimes Do-It-Yourselfers, and some shifty HVAC techs, can terminate their condensation drain lines in places they should not. Look at the picture below. What's wrong with this?

HINT: Why is the little tube connected to the big tube?

A closeup below gives a better look. The big pipe is the main waste drain line of the drain, waste and vent system. The drain line where all the bad, smelly stuff goes. Why is that little plastic/composite drain line plumbed into the main waste line? And should it be?

ANSWER: It shouldn't be. That small plastic drain is a condensate drain line from the condensate drain pump shown above. These condensate drain lines should not be connected to a component of the drain waste and vent system because this provides a path for waste system gases to backflow into the house or building. Plus it looks like it's leaking. What a mess! This is exactly how the condensate drain line should not be terminated!

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Thank you,

Richard Acree

Comments in this article are the copyrighted intellectual property of Richard Acree, President, HABITEC Home and Building Inspections, LLC, and are intended to educate and otherwise assist home owners, sellers and buyers, building owners, sellers and buyers, realtors, real estate investors, property managers, and lenders in the process of owning, buying or selling homes or commercial buildings. HABITEC is a residential (home) and commercial building inspection company serving Middle Tennessee including Nashville, Brentwood, Franklin, Murfreesboro, Smyrna, Mt. Juliet, Hendersonville, Dickson, Belle Meade, Columbia, Spring Hill and more! In addition to building inspections HABITEC offers Environmental Services for mold assessments, radon testing and water quality analysis. Additional information about HABITEC can be found on our website at, or call 615-376-2753.

Richard Acree is the author of the HABITEC Home and Building Inspections Blog and founder of the ActiveRain Group Tennessee Home and Building Inspectors. All are welcome to join and see more blogs like this one.

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