I live in Florida, I keep two things on hand for my HVAC drain line. First is condensate cleaner (less harmful to the plastic than bleach) which I use monthly and my backup is a Gallo Drain Gun. Even on my worst blockages, 2 shots of the drain gun cleared it out.
this post was submitted on 13 Sep 2023
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condensate cleaner (less harmful to the plastic than bleach)
Do you have a brand or version (looks like there is liquid and tablet) you’d recommend? I think it’s a good idea to start with this monthly.
I had a blockage that left puddles in my basement when were running the ac a lot during July. A couple of the blue ac safe tablets took care of it.
Something like this?
Looks similar. I got whatever was available at home Depot or Lowe's.
Can't say I've seen much difference, In my case, there is a place inline in the drain tube to pour in liquid so I use Algaecide in that but if you don't, use the drain pan tablets -- no idea which would work better though. It does work best as a preventative before you get buildup. My drain line is long with many twists and turns, lots of places ideal for buildup (I curse the builder for this!)
My drain has a float switch. If the line clogs and water backs up, it turns off the unit. I also have a leak sensor in the pan that integrates with my security system.
A permanent fix would be a larger drain or a backup drain.
My shit is pretty old and there isn’t a float switch. We’re planning on a full replacement next year so maybe this is the answer.
A float switch is cheap and easy to install, but I would hire a pro to do it.
Water sensors are a cheap investment that can be reused later. You can also buy inexpensive ones from Tuya or Aqara that are smart and should be able to notify you on your phone over just a simple one that beeps.
And if the unit plugs into an outlet there are smart adapters than can cut off power at a signal from the security system.
Not exactly a "fix", but a water alarm can ensure an overflow doesn't go unnoticed... but then you've got a battery to remember.
That said, the ones I have under my sink and near my water heater have been running on the original 9v battery for over 8 years now
I actually have one but it’s sitting in the water heater pan 1 foot away… I’ll get a second one right now.
Pour bleach down the tube once a month. There’s usually an opening for it.
There is an opening… I might start this. Change the filters and feed it some bleach
My AC guy said that it prevents the sludge that’s trying to grow in the drain, from blocking it. Set a calendar reminder and do it once a month.
Just a little, like half a cap, is all you need.
Do maintenance on the air filters. The water is being condensed straight from the air so it’s not hard water or anything. The only explanation is that enough dust is settling in the water that it clogs the drain. There must be some kind of air filter upstream of where dust can collect in the water line, and that air filter probably needs replacing.
The cheaper/lower quality the air filter, the less particulates it filters from the air. What dust the filter doesn't catch cycles through the system and can get caught by the AC coil. Filter effectiveness is measured by its MERV rating. The higher the rating, the more particulates it will catch. I use a MERV 13 filter but that's because I'm alergic to the entire planet and it helps reduce airborne allergens. If you go much higher than that your furnace/air handler may struggle to blow air.
Get some of those ac pan tablets. Or pour some bleach in the pan a couple times per year.
What's causing the clog?
I'm assuming this is a split unit? I don't have one, but I thought there was a float protection to prevent the AC from running if there was too mich water in it. Of course, this would probably only work if the clog was near the unit itself.
What's causing the clog?
The clog is “gunk” but I’m not sure what is actually causing it.
When I hit it with the shop vac I can hear it clearing a blockage of MISC gunk.
"Gunk" is probably a combination of algae sludge plus any captured lint from the ventilation. Not much to do about the algae other than blast it with a disinfectant like bleach once in a while.
How's the incoming air filtration into the unit? Is it sealed reasonably well at the filter?
Pretty good other than I could probably be a little more diligent with my filter changes. I do it monthly(ish)
Ah yeah, then a little bleach when you do your monthly maintenance will probably help that drain out a lot.
Preventative maintenance.
As you said, takes years to go bad.
So take the 10-15 minutes of time it takes to clean the duct, once a year.
And start making a list of things you can do preventative maintenance on.
If you can't put in a float switch, a drain snake once a month should keep it clean.
I have a similar issue. My line is coming from the 2nd floor and there is a pipe in the wall that drains outside newr ground level. The pipe is probably 12 foot long and takes a few bends.
I used a snake to clear the line a few weeks ago. Not entire sure what exactly is causing the clog but like you said, it's probably just gunk.
Now after I cleared the line I was ready to pull the drain out, but the pipe is like 1/2" so the snake isn't really blocking any condensate from dripping down. So for the last few weeks, I've simply left the snake in there. I'm thinking with the snake in there either maybe the gunk won't grow to clog the line so easily, or since it's already in there, all I have to do is wiggle the snake once a month and dislodge anything that might be starting to grow.
The reason I don't pull it out is because with the angle and bends in the pipe, I had a hell of a time snaking the snake up there. But once it was up there dislodged the gunk took all of 5 seconds.
The snake looks to be regular steel which will rust with water touching it, so I've ordered some stainless steel wire which I will run up the pipe ans just leave it there. It's not the beat solution but I don't have access to the source of the condensate so I have to work backwards from the drain up.