Flushing Air Conditioner Condensate Line?
 

New in TV and going thru The Villages "Home Owner's Maintenance" recommendations list. One of the items is "Flush Condensation Line with warm water" every six months. I'm curious about techniques folks are using to keep that line draining properly.

In our new home the condensate line comes out of the AC, drops down a couple of feet into the slab, runs under (thru?) the slab for 25-30 feet then comes up in the side yard and ends in a gooseneck about 9" above ground. That's a lot longer run than I've ever seen and seems like it will be susceptible to pluggage. There's a cap on a tee in the pipe run near the AC unit that is removable for pouring or pushing something into that line. It seems to me that just pouring a couple of gallons of warm water into the pipe would not be enough to keep such a long run flushed out. Can you use a hose to feed a flow into the line? - thinking that pressurizing the line might push water into the AC unit and flood there. Anyone use a chemical to add to the poured flush water to help stop slime growth without damaging the pipe? Am I overthinking all this? (probably - that's a common problem for me...).

Thanks for any thoughts.

I modified mine With cut off valve to prevent back flow and use water pressure to flush it out takes about 5 mins. Some use compressed air/ shop vac. This has been discussed several times. Do search or look in “ do it yourself”.

I sent you a PM Len

I just use the "blower" side of my shopvac with the small round attachment then throw in a cup of bleach. LOT'S of crud comes out the other side. :D

I don't worry about it, I have the A/C serviced every 6 months and they flush the line as part of the service. In our previous home we had to replace the heat pump and I had the new one serviced twice a year. When we sold the house the unit was 17 years old and still functioning properly. A heat pump is just like your car, it needs regularly scheduled maintenance.

Our AC stopped working after the condensate safety valve kicked in which disables the AC...tstat in house display went blank. Light compressed air and then hot water restored all.

The situation you describe. I had a new AC installed and neglected to clean the line. The condensation line got more and more clogged. I would at first get intermittent stoppages as the condensate level reached the safety cutoff switch. But it would come back as the condensate gradually seeped out. As the season progressed it became more of a problem to the point where I discovered the blockage. I tried the outlet air from a wetvac with no success. Then took a hose with no metal fitting and shoved it into the drain line. Taped it in place to seal the connection. Turned on the hose and it cleared it immediately. Since then, I use that method as a preventative. I think better result than hoping vinegar/bleach will work. Takes a couple of minutes to set up and you know immediately that it worked.

Twice a year pour a couple ounces Dawn liquid soap in the line and chase it with very warm water. I have a 25 foot run from the air handler to the end of the condensate line. Never have had a problem in 15 years.
I got this tip from an AC service professional.

Don’t overthink it !
 

It cost me $140.00 to learn to suck the dirty water clogged with algae with a shop vac. Refill the line with fresh water and add a couple of ounces of vinegar every couple of months. That’s it.

Half a cup of water mixed with half cup white vinegar once a month has kept ours clean for 16 years...

I was told by a/c man a couple of years to pour 2 gallons warm water down it every month instead of waiting for 6 month check ups. My unit is 8 years old. Takes 5 minutes once a month.

I was told to pour a gallon of hot water down the line every month. I have been doing that for the four years we have been here. During the annual service the tech uses a hose and with the pressure of the water from the hose also cleans it.

Thanks!
 

Thanks everyone for the good feedback! All of these approaches sound good - I’ll just pick one and be consistent about using it. From looking at the variety of options it seems like the consistency part is the key.

I used antibacterial soap in a gallon of warm water once a month poured into the drain. However, due to the length of the drain, I was experiencing blockage and backup to such an extent that the boxed area where the A/C sits became water logged. I had the drain reconfigured for a shorter run and the boxed area rebuilt. Since I had installed a new A/C unit in 2019, my contractor covered the cost of repairs. I will still use the soapy water in the shorter run.

We have our unit checked 2x a year....once the drain pipe backed up

I now pour a couple of quarts of boiling water down the pipe every 3 months...I was specifically told to not use bleach as that will cause issues

Make an adapter to attach to your garden hose. The adapter is a piece of flexible tubing that will fit inside the PVC drain. The flexible tubing should be 8 to 12 inches long, that way, the water you put in the PVC will be well beyond the tee connection going to the air handler.

Thanks. I photocopied your response for future use. This whole thread has been very helpful. I have a home in GA and a Villa in TV. In GA I change my condensate pump every other year -$50. I was wondering where the pump was located in my Villa. Now I know. They simply forgot to install them in TV. Lol

When Munn's service came over they flushed the line with the garden hose. They did that at the tee where the cap is located.

I have used a cup of plain white vinegar followed by 2 cups of warm water once a month for the last 19 years and no problems at all, don't use bleach, left over fumes can harm metal parts in the air handler, use vinegar.

Most AC companies use a small vacuum to vacuum the condensate line for 15 or 20 minutes minutes. Then pour a gal of warm water into the line at the air handler and vacuum again. The line exit is usually located at the outside condensing unit.
NEVER use Bleach. The chlorine fumes will corrode the evaporator coil in the air handler.

Just had this problem in June with our A/C. Our A/C guy said to put 2 cups of white vinegar down the line (A/C NOT running!) every 2 months and the line will stay clean.

I have my unit serviced twice a year. They flush it out. All part of the maintenance. Never had a problem. .

We do that too. Ours is 17 years old. Plus we run plain hot water through once a month. Yes, crud still comes out. It’s still working great and no corrosion in the unit from chemicals being used.

This was my thinking originally...if warm water is good, then boiling water will be better. However, an AC repairman cautioned me on that. He said the glue on PVC pipes is meant to distribute domestic hot water which may be about 140-150 degrees, depending on how high you set your water heater. But the glue is not rated for 200 degrees and too many cycles of 200 degree water will cause the glue to fail. Then, you've got a leaking connection beneath your slab.

My instruction book says to mix 1/2 cup of bleach with 1 cup of water and pour it into the drain. Really simple and works great. Been doing it for 21 years, about every three months. I have twice a year service and the drain gets cleaned when that is done.

My service company, Sunshine told me to pour hot water with some Vinegar down the line once a month. No problems in 11 years.

just use vinegar. Gets rid of the mold!!!

Yes, an old wash machine hose cut about 12" attached to your garden hose to get by the tee so the water doesn't back into the air handler. I use simple green, then flush.

warm water and white vinegar 50/50

Pretty similar from my AC company. For some reason (?) my Trane had no safety cut off (???) so had a puddle of water on the furnace pedestal before I realized what was happening. I used the tablets you just drop into the line for a long time after that, but AC person told me that a cup of vinegar would do the same thing much cheaper as long as I set a day *first day of the month, and do it every month without fail. For over a year had worked just as well as the costlier tablets ! Bought the super size Costco 1.50 gallon size to put out in garage to remind me !

https://www.talkofthevillages.com/fo...an-out-273001/



Here how I solved my problem. Takes less than 3 mins.

I flush mine 1st of every month with hot water and about 1 cup of bleach - been doing it since we moved in Dec 2009 - Never had a problem with it plugging up;also connect hose every 3 months (I can screw hose on mine) and force water through the drain. I passed this to my neighbors when I moved in and as they moved into our street. Of those who didn't listen, their drains plugged up and water flooded there a/c area - yes they had a/c service annually. Trust me, many of those doing service don't flush out the drain.

You might try ordering a "Drain King 345" attachment for your garden hose to flush it out every few months. Check drain line size before ordering.

Again, thanks for all the feedback folks. Much appreciated!

You can order a Drain King 345 device from Amazon for $11.70. It attaches to your garden hose and will flush water through your condensate line in a few minutes. I don't understand why anyone would hire a highly paid HVAC technician to flush out a simple plastic pipe.

Clever device. Looks like it might make a good tool for a doctor as well. ;) Gonna try a modified version of Topspinmo's contraption first because I can build that for about $2.00.

Every six months pour 50/50 of a water and bleach mixture down the line. This will keep it open and prevent a blockage that can back up and make a mess.

PERFECT! Best $11.70 "fix"for A/C drain. Just make sure you push it ALL THE WAY IN. Some Amazon review dummy didn't RTFM and he had quite a mess.

I just flushed my condensate drain with the Drain King 345. Even though I had been pouring vinegar down the drain every several months, when I flush it, I get a load of white calcium lime flakes out the discharge pipe.