AC Drain Clean Out
Heating and Cooling, Interior, Repairs and Installation, Video by Danny Lipford
If your home is equipped with a central air conditioning system you may have noticed a drain line on the outside dripping water near the air conditioner. This line drains condensation from the inside air handler to the outside. If this line clogs (usually from algae) it can cause water damage inside the house. You can prevent a clog by simply pouring a cup of household bleach into the line from the inside. To remove a clog once it has occurred, attach a wet/dry vacuum to the drain line outside (removing the paper filter first) and suck the clog out.
April 21st, 2007 at 4:17 pm
Hi,
Thanks for your advice on cleaning the a/c drain pipe. I did use a wet/dry vac and poured bleach as you described. However, I continue to hear excessive leaking into the drain pan below the unit. Should I be alarmed at this &, if so, what should I do now?
Thanks for the help,
David
April 27th, 2007 at 11:43 am
Thank you. It works. I fixed it in 30 minutes
Nicholas Roussos Says:May 3rd, 2007 at 1:53 am
I discovered my AC drain line was dripping under my ac unit tonight. Luckily, a friend had a wet/dry vac, and it was fixed right up before any damage occurred.
Great tip!
June 18th, 2007 at 5:15 pm
my drain pipe is leaking considerably, but there is no water in the drip pan underneath the unit in the attic. what could cause this constant dripping of water?
Nicholas Roussos Says:June 19th, 2007 at 9:33 am
Gary,
This is pretty similar to what happened to me. In my case it turned out that after the drain pipe clogged, it cracked. Check the drain pipe for cracks or leaks coming from it.
July 31st, 2007 at 12:32 am
How do you accomplish the same task when living in a condo?
August 4th, 2007 at 11:08 pm
Hello,
I can use some advice. A friend of mine noticed that a rubber hose that’s connected to a pipe that comes about 2 inches underneath my roof. I know it’s connected to the AC unit in my attic. My friend said allot of water seems to be coming out down that hose. So my question is - Is this normal? It was 95 outside today and 74 inside my house. The ac is working great so just checking about the excess water. Thank you
Ben Erickson Says:August 7th, 2007 at 5:31 pm
Richard,
One of the main ways an air conditioner cools your house is by removing humidity from the inside air which makes the air feel cooler. This excess moisture then flows through the drain line to the outside of your house. So what you are describing is probably a good thing. Just to be safe, I would go up in the attic and check to see if the unit is draining okay and not backing up in the pan. Also, be sure the water that is coming out is not running down the siding which might cause it to rot.
August 8th, 2007 at 10:18 am
I have checked to see if the pan has water in it, and it does not. Could it possibly be that the amount of water coming out the drain pipe is correct and I am concerned over nothing? It is strange to me that no water has come out of this drain pipe in 4 years, now, it is draining regularly, about a 5 gallon bucket every 2 or 3 days. It drops to the ground under the eave and is basically flooding that side of my house.
Ben Erickson Says:August 8th, 2007 at 11:15 am
Richard,
An air conditioner in a humid climate can remove quite a bit of water, so I wouldn’t say the amount you are seeing is unusual. What is unusual is that it didn’t produce any before. To keep from flooding the area under the drain, you could attach a pipe or flexible tubing to the drain, run it down the side of your house, and then attach a hose to direct it elsewhere. By the way, the water that comes out of the AC is distilled water and is great for watering plants or a garden, so perhaps you could direct it there or to a pond or holding tank for later use.
August 8th, 2007 at 11:16 am
Ben,
Thank you for your advice and help. I check the pan and it’s dry so I assume everything is draining properly. With the hot weather and the dry humidity we are experiencing in Houston, Texas I just wanted to make sure the draining water was due to the weather changes. The previous owner had a rubber tube installed over the pipe piece that the water is draining out of so that the side of the house isn’t effected. Thanks again for your advice and help. I fee much assured now.
Thx
Richard
August 22nd, 2007 at 2:20 am
I just noticed the same problem as Richard (I’m in Fort Worth, TX). My unit is filling up a 5 gal. bucket every day. A tech came out and said he blew out “both lines” and they were fine. He noted on the sheet that the emergency and primary drain ran together and then outside the house.
This seemed strange to me and I went and looked myself. This is a Trane handler unit in the attic. There is one white PVC pipe coming out the bottom that goes over to my master bath area. It has a removable cap on it. I removed it and it had water up inside the tube and did not appear to be draining. A second PVC pipe comes out of the unit, joins up with a PVC pipe coming out of the drain pain and then runs outside under the eave of the house. This is what has been running with water. The drain pain was dry.
I removed the cap on the one PVC line that ran to the bath and poured about a cup of bleach (in 3 portions) in the opening. The water in it got air bubbles in it, then went down and you can see a slow trickle running in the pipe now. Also I can feel air blowing through the pipe when the cap is off and the unit running. But now, there is a very slow drip of water into the pan coming from where the PVC pipe that runs to the bath connects to the handler. Maybe I jiggled it too much. The outside pipe seems to have stopped flowing.
So now I’m confused about what the tech said and whether I blew $85 for nothing. Wouldn’t the PVC line that runs to the master bath area be the primary drain line? Doesn’t seem like they run together to me?
August 23rd, 2007 at 12:53 pm
I need some help. My AC handler is inside a small closet in my house. The drain pipe from my AC unit is working fine, but at the floor it terminates into a larger pipe that another insulated tube runs as well. I found that insulated tube outside my house at the outside unit, but there was no larger pipe for where the drain pipe leads.
Water is backing up out of this larger pipe at about 3-5 gallons per day and I am continually pumping it out with a wet/dry vac. How do I unclog this larger pipe from inside my house?
September 16th, 2007 at 9:45 pm
Hi Rob, im wondering if you found the answer to your problem……..im having alot of drainage in my CARPETED garage……….and CANNOT find the drain either!!! yikes!!!!!!!!!!1
October 1st, 2007 at 7:46 am
Hi Vicky,
I’m not sure I really found a solution to my problem. I dug a hole near the foundation and AC unit outside my house and found where the smaller pipe comes out. I snaked it and cleaned it out and filled most of the hole with drainage rock.
So far I haven’t had any backup into the larger pipe in a few weeks. Hopefully it will stay that way. Good luck.
October 8th, 2007 at 6:00 pm
I have the same problem, water isdripping on the pipe in the unit, but the actual end of the pipe , the other extreme, is inside the wall I guess going underground, have not access to it, shouldI just pour some bleach on the pipe and see what happens?
October 11th, 2007 at 12:51 am
The drain pipe for my AC is leaking. We can’t figure out why. The drain pipe is clear, no clogs, we blew it out and poured bleach in it. It worked for about 5 minutes and then started leaking again. It backs up into the pan and that leaks all over also. What is going on? This happened to us before and the excess water in the pan ended up shorting out the fan motor. So for now we’ve disconneted the drain pipe and have a bucket under it so the water can flow freely into the bucket instead of backing up into the pan. Any suggestions?
October 11th, 2007 at 10:21 pm
I live in a condo and my drain pan was filling up and not draining to the outside. Could you tell me why this would happen as I have a brand new unit….could it be from person downstairs they have old unit. If theirs was clogged up would that back up to the 2nd floor unit???thank you
October 16th, 2007 at 12:10 pm
I just purchased my home in July. Our A/C has been working with no problems until it started leaking 2 weeks ago. I then paid $150 for someone to clear out the line. Five days later it was leaking again. Purchased a wet/dry vac, poured some bleach in the line on the inside, and then vacuumed the line from the outside. A large amount of algae came out. This did not reslove the problem. Even tried putting my hand over the other end of the pipe for more suction. After doing this, there was a lot of suction. I thought I had it. Still leaking!! The only idea I have left is that there is something wrong with the drain line. Maybe it cracked? I have my washer close by the A/C unit and thought of having the A/C drain through there. I am running out of ideas.
October 18th, 2007 at 2:58 pm
We have 4 A/C in three different house’s
& in one the pan below the upstairs unit bent & leaked water in the ceiling.
I blew the lines out with air & called the A/C owner & he said that they had had problems with the pans lately, & said that they have float valve that they had been putting on the units & he had them in stock.
he sent a man out the next day & he put two in one house & one in another & the man could not find it in his book so he said that he would have the office call me with the bill when he got back in on monday, well they called me about two weeks later & ask for a cordite card number & then I got the invoice’s I had paid $140.00 each for the float valve & switch’s a total of $578.00. The reason the tech. could not find it in the book is that the book is the book shows P trap & all & he said that he had not installed a P trap & did not know what to charge.
Folks The switch assy is PVC T & a switch setting in the top which shuts the unit down when the line gets stopped up the whole assy . should not have cost them over $15.00 Bulk (PVC parts are Cheap.) the moral is always ask even if you do know the people, I have known these people over 19 years.
Another thing is 4 straps is not enough when the pan gets stopped up, I had him put two addicional straps on it (One on each side in the middle)
Bob
October 19th, 2007 at 2:16 pm
After someone cleared out the line, another tech cut the pipe on the inside so we could clean it through there. When he was finished he put a fitting over the opening. When it backed up again after he had left, I took the fitting off and placed a bucket underneath. It started to drain normally. When I put the fitting back on it would backup. I finally left the fitting off and put duct tape around the pipe instead. I also leveled off my overflow line. I have not had a problem since.
October 19th, 2007 at 10:14 pm
I have had problems with drain in garage floor, on very hot days when air runs alot. after reading this site…..i tried some bleach down the drain not sure whether it helped or not…no more leaks lately b ut not as hot out either ……i could nt find the outside drain that was spoken of..is this likely the problem……could the drain line be inside the fan unit???? or underground???? trane unit.
October 23rd, 2007 at 5:40 pm
The tricky thing about AC drains is that the air handler usually operates in a negative pressure as it pertains to the drain side-which is the reason for the trap.If the trap isn’t deep enough then the water will get sucked back into the unit,then when the unit cycles off the extra water may overlow or drain so rapidly that the drain line can’t handle the amount of water.Another thing is that if the drain is longer that 10 feet after the trap-the line needs a vent after the trap so the water will not cause a siphon effect on the trap.
February 15th, 2008 at 12:02 pm
You want your AC to drain. The pan under the unit is only as a last resort so the condensation does not damage your walls. What I have found in Texas is this, the primary drain is the closest interior drain in the house, but not the washer drain. The secondary drain is overboard. If you see water from this drain you should investigate. What I see often is the primary drain is plugged by the stem pipe not being trin at installation. If you take the drain pipe off the sink, trim it above where the AC drain is plumbed, clean out the pipe as other have stated, then tada, no more leaking outside.
March 31st, 2008 at 1:04 pm
Could a clogged drain be the reason that I have a mildew smell coming from my AC whenever it is turned on?
May 26th, 2008 at 11:34 am
Hi,
I just had a AC man out here. I replaced all the flexy ducts up in attic. Right now it is 84 degrees. I turned it on about 3 hours ago. Home is set for 70 and it is fine in the house. Problem? There is no dripping outside the pipe like last year. My question is. Is there no dripping because the house is not humid? Is that possible? Also, I did the wet vac outside like you said on the website. I went up in attic and nothing is freezing up and no water on floor. Thank you
June 4th, 2008 at 4:59 pm
Problem? Went away on vacation for a week. Returned to find that ceiling and walls in laundry room soaked and discolored. Checked attic and found that the drain pain was full of water. Called AC tech and he blew out drain; however, the ceiling is still leaking. Any other suggestions
June 6th, 2008 at 3:06 pm
Hello,
My Central A/C unit is located in my utility room. It was replaced 4 years ago. Last year, I when I went to the utility room, I could hear drip, drip, drip. Apparently, the condensation pipe is not connected to drain outside, but instead, just drips steadily into my crawl space (which is sand/clay). The A/C is near a back wall, about 7 feet straight ahead; should I have a plumber (or HVAC professional), run the condensation drain pipe to the outside (could go through the foundation), or to the sump pump, which is about 30 feet away from the dripping pipe?
Please let me know the best way to take care of this problem (most econcomical, too).
FYI, I live in a duplex, and our units are not separate by wall. In fact, our units are right next to each other. Her pipe is dripping the same way too.
Look forward to your prompt response.
July 1st, 2008 at 2:59 pm
George from Austin, TX here!
Just a tid bit of info to help a few of you out.
If you are vacuuming the primary line with little to no luck, that probably means that the clog isn’t that well developed and not letting you get too much suction.
Have a friend/spouse go to the AC system and plug up the bypass line with their hand (i used a 1/2 pvc cap i had lying around). This will give you a more solid suction and pull out the gunk.
I was trying for 3 days to suck the garbage out of my drain…. bleach wasn’t working either.
I tried the cap on the end of the line when i though that maybe the algae is built up on one side of the pipe and not letting me get a good seal.
It literally took me 10 seconds with the cap on the bypass valve!
Hope this helps!!!
July 3rd, 2008 at 3:29 pm
The air conditioner drain pipe in my house is enclosed and it is attached to a drain that goes under ground from inside the house. Will this drain pipe still need bleach poured in it anually?
August 9th, 2008 at 4:43 pm
We had a man come in and fix the basment for leaking and while he was doing so he decided to fix a AC problem so he took a pipe to move the water from the unit but he only moved it about five feet away so now water pools near the side walk in my back yard and looks really ugly please help what can I do !
August 24th, 2008 at 6:42 pm
I have a similar problem but my main drain lines drains into the wall and i assume into a vent pipe which goes to the sewer. The secondary line is dripping and there is a small amount of water in the pan. There is an access pipe into the main drain line. Will the vacuum work to suck out the clog since it is located in the attic or should I try something else?
August 29th, 2008 at 8:59 pm
I live in a 6 unit condo building, 3 on one side, 3 on the other. I’m the middle unit. My AC unit itself (the fan part) is located outside. My furnace is located in the center of my unit next to my washer dryer. Coming out of the bottom of the furnace is PVC pipe that runs into a small “hole” in the floor, that is another PVC pipe. I can only see the top of the PVC pipe and have no clue where it runs, but it does run into the ceiling of the unit below me and outside, I assume. I looked and can’t find it. I had a guy come out 2 years ago when this happened and he said the pan needed cleaning. The guy below me complained of water on his ceiling. I looked down that pipe and saw standing water. Should I use draino or snake it or use a vacuum? Thnaks for any help.
September 1st, 2008 at 2:37 pm
This morning I noticed condensation on all my AC vents both wall and ceiling. This has never happened before. I wipe the vents but continue to get condensation and dripping.
I have a Trane unit and the drip pan and coils are in a sheet metal inclosure inside the unit. Should I remove the sheetmetal cover and check the pan drain? I have already cleaned the drain going outside.
September 11th, 2008 at 4:04 pm
I had a clog in drain line from the air handler and my primary drain pan under the coils filler up and overflowed into the air handler unit and got the insulation all wet. I can’t seem to dry it out. How do I prevent mold from building up??? I can’t remove the insulation under the pan unless I remove the coil which is very expensive. Is there anything I can do about this??
September 19th, 2008 at 6:54 pm
I am not what is going on with my pipes but there are two ‘drain pipes’ outside of my house not the one near the ac unit and it is draining alot of water out and I dont know why and where it is coming out at. Can some one help me with this? One pipe has alot of warm water coming out of it the other one dont have any water coming out.
September 28th, 2008 at 9:20 am
I also have the reoccurring problem of the trap getting plugged. At least once a year, I have had to crawl up into the attic and unplug the drain. I have added a pipe (with cap) to add bleach but still get the plugged trap. I just had both knees replaced and it is difficult to get up on the six ft ladder to do this maintenance. Can I eliminate the trap and use a straight pipe instead? I noticed the pipe is very loose where it fits to the AC unit. It acts more like a funnel to catch the condensation. Any negative air or vacuum would be lost anyway. Thanks for any help here and all thoughts appreciated.
ernie
September 28th, 2008 at 9:02 pm
Note: I was wrong about the main drain line being loose and open. That Line is from the humidifier. I don’t know if that needs to be sealed or not. Again,,,, thanks.
ernie
September 30th, 2008 at 10:42 am
Thanks for the great information…..my husband is gone all the time and I’ve become the the fix it all girl! Had the AC man down the street help and he did not fix my problem…just goes to show a little research, and even a woman can do it! Bless you!