When good condensate drains go bad, property damage may result. Central air conditioners produce something other than cool comfort: water, lots of it. Because dry air holds less heat energy, humidity extraction is a critical part of an efficient air conditioning process. When the air conditioner blower pulls warm household air through the frigid passages of the evaporator coil, the cooling effect causes water vapor to condense out of the air rapidly. Condensation drips down into a collector pan under the coil and is conveyed through a drain line to a household sewer connection. Things that might go wrong in the condensate drain system include damaging leaks, bad air quality, toxic mold growth, and even a complete air conditioner shutdown. Leakage And Overflows The wet, warm environment of a condensate collector beneath a central air conditioner evaporator coil is a perfect algae breeding ground. This biological growth may migrate into the condensate drain line or the drain trap and form a blockage.

Condensate overflow due to a blocked drain may be caught by an overflow pan beneath the air handler, but if the overflow pan is missing, or has cracked or developed a hole, or if the overflow pan’s drain line is plumbed to the same primary drain line that is clogged, water leakage will ensue. Property damage from unseen condensate leakage can be extensive and expensive by the time a leak is finally noted by occupants. air conditioning units mounted on wallDrain Trap A central air system routes condensation through a U-shaped trap located in the drain line just outside the air handler. federal tax credit ac unitIt's similar to the trap under your kitchen or bathroom sink; how to replace home ac blowerwater in the trap prevents sewer gases originating where the condensate drain pipe terminates from infiltrating the air handler.

In some conditions, such as during a long season of non-operation or when a gravity-fed drain line is not installed with the proper incline, the condensate drain trap may dry out and allow sewer gases to pass through the line. Unexplained noxious odors emitted from air conditioner supply vents in the home are the primary symptom of a dry condensate drain trap. Mold Growth Mold in the condensate drain system feeds off tiny airborne organic particulates sucked in through the return ducts and produces millions of mold spores. A mold colony is perfectly positioned to disperse spores into airflow in the supply ducts, and to infect the breathing air throughout your home. Allergic symptoms and other respiratory distress may result in susceptible individuals. In addition, mold growth originating in the condensate drain collector frequently expands into the evaporator coil, too, obstructing narrow air passages and strangling system airflow. System Shutdown Because of the potential of severe property damage from unseen leaks, many condensate drain systems incorporate an overflow sensor.

When a clogged condensate drain causes a backup that reaches overflow stage, the sensor cuts off power to the system. The coil and collector are sealed inside the air handler and generally not accessible for a do-it-yourself project. Until an HVAC technician can arrive to open the air handler, unblock the drain line, and clear the pan, the air conditioner will be unusable. References Inspectapedia: A/C Or Heat Pump System Condensate Drains, Piping, PumpsAmerican Society Of Home Inspectors: Let's Concentrate On Condensate Photo Credits Jupiterimages/Stockbyte/Getty Images Suggest a CorrectionA/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. 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: Using a CO2 cartridge to blast out a clogged A/C or heat pump condensate drain line is a method followed by some service techs. Heating or air conditioning equipment suppliers sell a small CO2 cartridge canister with an outlet adapter and fittings to connect to various sizes of piping. The canister is connected to the condensate drain line inlet (and the vent at the drain plugged with an expandable rubber plug sold for that purpose).

A CO2 cartridge is dropped into the canister and its cap screwed on. Screwing the canister top on tightly will puncture the CO2 cartridge, sending a quick shot of high pressure gas through the drain line, clearing an obstruction. (This method is also widely used by oil heat service technicians to clear a clogged heating oil line.) We have found this a very helpful tool that will sometimes blast an obstruction through a condensate drain system. However in working on split system air conditioners whose condensate drain opening is difficult to access you may find that you cannot get the rubber condensate drain line plug securely in place. See SPLIT SYSTEM AC CONDENSATE LEAK REPAIR Vacuum clean the clogged condensate drain line: Use a manual pump to vacuum clean a clogged air conditioning or heat pump condensate drain line. The pump inlet side is connected by an adapter fitting to the condensate drain line opening. You'll have to plug the nearby vertical standpipe at the condensate trap if one is provided.

The manual condensate drain line pump's outlet side is connected to a hose run into a bucket or a nearby building drain to receive any waste. Portable pumps for condensate drain cleaning include A/C Drain Sucker from ClenAir Manufacturing, Inc., P.O. Box 346 Drain Dawg & Clear Vue Condensate Pump from DiversiTech. Little Giant Condenate Drain Pump. In December 2014 the company's website was not working but their products are widely available from plumbing and HVAC suppliers. Mighty Pump - we removed the live link for this product after a reader reported that the recommendation for this device was posted by Stuart Oakner the owner of the company who posted suggestions without so identifying himself. Details are at FAQs in this article. InspectAPedia is an independent publisher of building, environmental, and forensic inspection, diagnosis, and repair information provided free to the public - we have no business nor financial connection with any manufacturer or service provider discussed at our website.

We 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. 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. You 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.