Photograph of drains to a hidden location How to Clean or Un-Clog an Air Conditioning or Heat Pump Condensate Drain Line or Trap

  • CONDENSATE DRAIN CLEAN & DE-CLOG - How to clean or de-clog the air conditioning or heat pump condensate drain line - detailed procedures, products, methods. A/C condensate drain line cleaning tools & products stop condensate drain line overflow: brushes, snakes, blow-outs, pumps, plumbing snakes or shop vacs all can be used to clear a condensate drain clog. But what is the quickest, simplest, least costly way to clear a blocked condensate line?
  • POST a QUESTION or READ FAQs about how to un-block a clogged A/C or heat pump condensate drain
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A/C condensate drain de-clog & cleanout: this how-to article explains procedures for cleaning or de-clogging a sluggish, blocked, or leaky air conditioning or heat pump condensate drain.

Condensate drain cleaning and unclogging tools and methods are reviewed, including simple steps that a homeowner can take to clear a blocked condensate drain at little or no cost.

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How to Un-Clog an Air Conditioning or Heat Pump Condensate Drain to Avoid Leaks & Damage

A clogged condensate drain can cause air conditioner problems or even loss of cooling

What Causes A/C Condensate Drain Line Clogging?

Photograph of drains to a hidden location A/C or heat pump condensate drains can become clogged, leading to condensate leaks, spillage, or even bacterial hazards in a building.

Clogged air conditioner condensate drain lines can form another source of air conditioner or heat pump condensate leakage that can in turn lead to hidden water damage or in some locations an indoor mold problem or bacterial contamination.

Our photograph of a nearly full A/C condensate overflow pan (at left) shows what can happen if the primary condensate air conditioner condensate drain line is clogged and worse, the condensate drain overflow pan is also itself clogged and not draining properly. Luckily we caught this attic mold and bacterial pond before it had soaked the ceilings below.

We see air conditioner or heat pump condensate drain lines clogging for several reasons:

How do I Clean an Air Conditioning or Heat Pump Condensate Drain?

Photograph of a condensate tray drain Photograph of drains to a hidden location

AirTech condensate line trap with cleanouts (C) AirTechProducts

CO2 air conditioner condensate drain cleanout blaster (C) Daniel Friedman

Condensate Drain Line Cleanouts, Access Ports, Blow-out or Vacuum-out Valves & Fittings

Easy Klear Easy Cleare condensate drain line cleanout (C) EasyKlearWe like the clogged condensate drain vacuum cleaning approach better than the blow-out approach if we can get this method to work because it is more gentle, reducing the risk of damaged piping, and because we minimize the risk of blowing a plug of crud downstream to a more distant location where it can form a new clog or plug in a long condensate piping run.

[Click to enlarge any image]

Several air conditioning and plumbing suppliers provide easy-to-clean air conditioning condensate cleanout ports such as the one shown above, including the Easy Klear condensate line cleanout (photo at left) that is particularly useful if your condensate drain line has a long run with a slope of less than 1/8" per foot.

This A/C or heat pump condensate drain line cleanout is intended to be vacuumed using a connection to a shop vac.

Jones JV-1 condensate line blowout valve available from Supco, Watso, Gemaire and othersYou should check out the Jones Valve, too, available at Supco and Watso, United Refrigeration and Johnstone, the latter two as "Line Drive".

Sources for A/C or heat pump condensate drain blow-out valves (remember our warning above?)

Watch out: Cleaning out partly-blocked, sluggish A/C or heat pump condensate lines: neither the vacuum method nor the blow-out method will work very well for cleaning a sluggish condensate line that is not totally blocked, since you may simply move air past the blockage rather than removing it.

If you encounter this problem, try hooking up your pump in the "blow-out" configuration, then try filling the condensate line with tap water so that the pump pressure can act mechanically on the clog.

Watch out: connecting a blow-out device or a vacuum device to a condensate drain that is connected to building plumbing drain waste or vent piping may cause some trouble.

These devices should work well for condensate drains directed to the building exterior but depending on piping arrangement (and eschewing for a moment the fact that DWV connections of condensate drains are not recommended without an air gap) using a shop vac you may pull wastewater or even sewage back into the condensate drain.

HVAC Condensate Articles


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