A/C drain line plugged, what to clear it with?

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The condensation drip drain line for my central A/C appears to be plugged again, with whatever it is that grows is such places and resembles clear jelly. A few years back I installed a coupling and valve, so I could wash it out with the garden hose without flooding my drip-pan, and this included an inlet to pour a dilute solution of chlorine bleach into the system, to prevent such clogs. That was probably ten years ago, and I haven't done squat with it since, so it is plugged again. Tonight I tried to close the valve, and it jammed on me before completely closing. I called that good, and ran a shot of water through the hose to it and cleared out the portion downstream from the valve. Upstream from the valve still appears to be something of a problem however. Was going to pour more dilute chlorine bleacn into it, until wife reminded me that she spoke with one of the building engineers where she works (major bank in a large metropolitan area, 72 story building,) who told her to tell me to *never* pour chlorine bleach into the drip pan of my central A/C unit. So I poured some 3 percent (stuff you buy at the drugstore) hydrogen peroxide into it instead, thinking that bacteria are carbon-based life forms, and that H2O2 will turn such into CO2 and water if it gets the chance (thus the foam from hydrogen peroxide on a scraped knee.) It appears to be working, even if it's not a block-buster cleaning agent. So I come here, to ask the A/C gurus, what *should* I put into the drip pan to clear out bacteria or whatever it is that grows in there? I know this place is populated by people in the know, and I now seek your advice. The drip line is draining, slowly, and the valve still won't close completely. So, what would *you* do?
Many thanks in advance to the people I know are out there who are already familiar with central A/C and it's problems.
Dave
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I'd disregard the other advice, and pour in the bleach like you should have been doing all along.
Hydrogen peroxide does not release CO2, it releases O2. Like when it foams, on a cut.
Christopher A. Young Learn more about Jesus www.lds.org .
The condensation drip drain line for my central A/C appears to be plugged again, with whatever it is that grows is such places and resembles clear jelly. A few years back I installed a coupling and valve, so I could wash it out with the garden hose without flooding my drip-pan, and this included an inlet to pour a dilute solution of chlorine bleach into the system, to prevent such clogs. That was probably ten years ago, and I haven't done squat with it since, so it is plugged again. Tonight I tried to close the valve, and it jammed on me before completely closing. I called that good, and ran a shot of water through the hose to it and cleared out the portion downstream from the valve. Upstream from the valve still appears to be something of a problem however. Was going to pour more dilute chlorine bleacn into it, until wife reminded me that she spoke with one of the building engineers where she works (major bank in a large metropolitan area, 72 story building,) who told her to tell me to *never* pour chlorine bleach into the drip pan of my central A/C unit. So I poured some 3 percent (stuff you buy at the drugstore) hydrogen peroxide into it instead, thinking that bacteria are carbon-based life forms, and that H2O2 will turn such into CO2 and water if it gets the chance (thus the foam from hydrogen peroxide on a scraped knee.) It appears to be working, even if it's not a block-buster cleaning agent. So I come here, to ask the A/C gurus, what *should* I put into the drip pan to clear out bacteria or whatever it is that grows in there? I know this place is populated by people in the know, and I now seek your advice. The drip line is draining, slowly, and the valve still won't close completely. So, what would *you* do?
Many thanks in advance to the people I know are out there who are already familiar with central A/C and it's problems.
Dave
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Hey, thanks for the reply. So, how dilute should I make the solution. Would a 10 percent bleach solution be strong enouch to do the job, but weak enough not to damage the galvanized drip pan? I don't remember what I used before, I just remember warnings not to make it too strong.
Many thanks.
Dave
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I remember 10% is the standard number.
Might be on the web some where.
Christopher A. Young Learn more about Jesus www.lds.org .
Hey, thanks for the reply. So, how dilute should I make the solution. Would a 10 percent bleach solution be strong enouch to do the job, but weak enough not to damage the galvanized drip pan? I don't remember what I used before, I just remember warnings not to make it too strong.
Many thanks.
Dave
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Just how do all you people propose to get bleach into the condensate line in the first place?
A blast of compressed air (as I described previously) is the most ergonomic method - assuming you have a small tank handy (borrow, etc).
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Home Guy wrote:

The bleach will have to be poured inasmuch as bleach won't miracle itself into position.
I trust that answers your question.
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HeyBub wrote:

No, it doesn't.
How do you pour something into a line and have it run *UP* the line?
Most condensate lines run DOWN from the pan inside the furnace plenum.
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It's PVC pipe. Just cut it, remove a section, unclog it, clean it, bleach it, whatever and put it back together with a coupling. Geez.
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" snipped-for-privacy@optonline.net" wrote:

I don't see where the OP mentions the type of pipe.

If you're going to cut it, then put it back together, you're telling me that it's worth the time and effort to clean it with chemicals vs spending $2 for a new section of PVC?
And that's assuming the section you cut is the section containing the blockage.
And we don't even know if it's made with PVC vs copper in this case.
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I'm telling you how to access the pipe to do whatever you want with it. Because as usual, you seem confused. Once it's cut you can do anything you want, including pouring something into the pan under the coils, if that's what he wants to do.

I've seen a lot of HVAC here in the USA. I've yet to see a residential central AC use copper for the condensate line. I've seen Holmes run around to a bunch of them in Canada on TV too and never seen anything but PVC. But then you're in your own little universe, so who knows....
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" snipped-for-privacy@optonline.net" wrote:

I'm making the point about dicking around with the clogged pipe with bleach because that's the direction this thread took, and I'm wondering why that's a better way to deal with the problem vs blowing it with compressed air.
I'm asking those that propose to use bleach how they make it run up the drain line. If you're not one of those proposing to use bleach, then why are you butting in now?
Those that are proposing to use bleach have yet to explain the entire proceedure - which according to you involves cutting the line. Nobody else has proposed that step.

It's not always the case that the coils and condensate pan are easy to get to - without taking the plenum apart.

At my office and home they are copper.

Apparently your universe includes poorly-designed systems, components or materials.
Unless the furnace / air-handler is located very close to (or directly over) a basement drain, then a plastic condensate line that is run across open floor to the nearest drain can be stepped on, pinched or otherwise collapse and block proper drainage. Naturally this collapse is more difficult when the line is made of ordinary 1/2" copper pipe. Also - copper might have bio-chemical properties that hinder the formation of blockage in the first place.
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Because YOU raised the question of how it would be possible to get a liquid into the drain line or AC pan.

I never said anything about getting to the coils and condensate pan.

Given your record here for sensationalism and pure hysteria, forgive us if we don't believe you.

Then there must be one hell of a lot of poorly designed systems out there because PVC is used in every residential system I've seen. And for good reason. It's a fraction of the cost of copper, it works, and there is nothing wrong with it.

Then that is the problem. You're dealing with half-assed installations that have nothing to do with the PVC or copper. I have yet to see PVC pipe get pinched or just collapse. Even if you step on it, it doesn't pinch or collapse, unless it's heated to 250F. And no drain should be run across a floor.

It's impossible if you do the drain right, instead of running it across the floor for people to trip on. Geeez...
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Have a cutout in the furnace plenum which was originally for a humidifier. Removing a cover plate provides complete access to the condensate drain pan. My bleach solution, therefore, runs down and out. MLD
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MLD wrote:

Do we know if the OP has similar access to the condensate pan?

If the bleach can find it's way down into the line -> then the line must not be blocked.
So again, how exactly is this bleach method a solution to a blocked line?
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Oren wrote:

Bleach (or anything else) can't flow into a blocked line, fool.
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Oren wrote:

Do you know how stupid you sound?
For most people, "appears to be plugged" = "plugged".
For most people, plugged = blocked.
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Bleach solution dissolves blockage---bleach solution then goes down line and out. Repeat several times and then maybe you'll understand how it works. MLD
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MLD wrote:

Fail.
How does it get to the place where the blockage is when there's going to be water (or junk) already accumulated above the blockage?
Maybe in a few weeks, months or years the bleach would diffuse into the line to the extent necessary to perform this magical unblocking...
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You've got a problem---you need to find something that will dissolve a mental blockage. Let's kindergarten this a bit------ Try this---forget condensate drain and think sink drain blockage. Have you ever heard of "Liquid Plumber or Draino"? You put it in the sink and then it mixes with the water above the blockage and somehow, magically via a chemical reaction, manages to eliminate the blockage. It really isn't a hard concept to grasp, you really can't be that dumb!
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MLD wrote:

You (and others) have a basic problem of being able to visualize the situation.

Oh, how dumb we really are.
For one thing, most people use liquid plumber or draino when there is at least *some* draining or flow still happening.
Second, draino crystals are heavy and will sink to the bottom where (presumably) they will directly contact the blocking material. This is aided by the fact that the diameter of your sink drain is large and the crystals can access or reach the blocking material, and the distance involved is very short.
Now, contrast all that with the A/C condensation line. It's highly likely that the average home owner will not be attending their furnace to the extent that they would notice the condensation line in the process of getting plugged (as they would with any sink drain in the house). It's only when the condensation line is completely plugged (and causing over-filling and leaking elsewhere) would the home owner detect a problem.
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