Your air conditioner does two jobs: It cools down the air and it dehumidifies the air. If you live in a dry climate, you want the AC to dehumidify as little as possible because it uses extra energy and makes you spend more on lip balm and hand lotion. If you live in a humid climate, you really want it to do that second job as well as it can to keep your indoor air dry and comfortable. But where does all that condensate go? In most homes, it goes outdoors through a pipe, like the one above. Sometimes there's a little pump that pumps it out, but most often it drains by gravity alone. Occasionally that condensate line gets clogged. This happened at my condo last week. (We live in Atlanta, Georgia, a mixed-humid climate.) Gunk in the pipe built up to the point where it was barely draining. We could run the AC for a little while and then we'd have to turn it off again. This past weekend I tackled the problem. One of the best ways to do so is with good old air pressure. If you can close off all escape routes except the one in the direction of the clog, you can shoot positive pressure into the pipe near where the indoor unit is located.

That should blow the clog out the other end. In our case, that wasn't an option because our condensate line is connected to our upstairs neighbor's air conditioner, too. So I got out my little wet-dry shop vac and set it up to suck the gunk out at the end of the pipe. The photo below shows the setup. I was hoping to avoid a trip to the hardware store, so I used red duct tape to try to make an airtight connection between the shop vac hose and the condensate line. wet around ac unit I took the shop vac hose with me to the store and bought some fittings in the plumbing department. portable ac unit for carI hooked it all up (photo above) and got a nice, airtight connection this time. use ac split unitWith the taped connection, I got maybe half a cup of water out of the pipe.

With the airtight connection, I got the bucket full of crud you see below. If you really want to see how bad it was, watch the short video below and you can see my wife pouring it out. Yes, all that gunk was in our condensate line. One problem with condensate lines is that algae can grow in them. In our case, there's also a lot of sediment in that bucket, possibly from a corroded evaporator coil. We replaced our AC in 2009 and the condensate line hasn't been cleaned since then, so some of that crud could have been from our old unit. If you haven't thought about your condensate line lately (or ever), this would be a good time to do so. You can have your HVAC company make sure it's clean, or you can get a shop vac and do it yourself. To keep it clear, you can use an algaecide that's safe for air conditioners. Your HVAC company can recommend one for you. In hot-humid climates like Florida especially, clogged condensate lines are a frequent problem. A little preventive maintenance now could save you thousands of dollars in water damage repairs and the loss of your air conditioner when the heat really cranks up.

This Thermostat Setting Can Cost You Money and Make You Sick Have You Seen What's in Your Hotel Room Air Conditioner? An Interesting Way To Freeze Your Air Conditioner CoilA/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.