AC Condensate Line Cleaning

Hi all, I have a 3 year old AC system with the compressor outside and the blower, furnace, etc... horizontally in my attic. A drain comes out of the system, goes through a p-trap and then splits with one branch going to a drain pan and the other has a vertical maintenance vent pipe and then (I'm told) goes on to tie into the house plumbing where it drains into a sink in the master bath. There is a line exiting the drain pan which goes across the attic floor and exits attic through the eve of the house. That point is dripping, telling me the drain pan is full and the main line is clogged, right?

My question is how to clear it. I can't get to the "far end" of the system to suck out any blockage with a vacuum, so I need to blow it out, correct? The problem is, if I just connect a compressed air source to the maintenance pipe and blow, what prevents the air pressure from just going backwards and going out the pipe that leads to the drain pan? Do I plug it? If I do that, then what prevents the pressure from going back into the air conditioning unit?

I'm also told to put a cup of bleach or vinegar down the line. Would that kill any mold/bacteria and clear the line that way, or will it probably need physical removal of the blockage?

This drain was cleared by the AC company less than a year ago and they put a chemical down it to prevent clogs. I think the blockages may be exacerbated by roofing deck wood chips that may have fallen into the maintenance vent pipe when we got a new roof installed. There wouldn't have been very many, I don't think, but it did not have a cap. Grrr!

What's the right way to do this? Any help appreciated. TIA.

-Dan

the condensate from the ac and the pan are separate indirect drains
if the pan has water in it
you need to find out why,
it is one of 2 things
the plenium is sweating due to lack of insulation, or sloppy installed insulation
or, the unit it self is not ''tilted'' to the condensate drain

you need to crawl up into the attic, by code,, it must be accessible for maintenance with a lighted walk way up to the unit
go look,,if it is sloppy insulation,,patch the insulation and buy a gallon bucket of ''duck butter''
https://www.lowes.com/pd/design-pol...7_c_&msclkid=d44a7734928d18e479512a362ac16669

the object of this game is to wrap the plenium with insulation and seal the insulation

the unit
the unit has a condensate drain on the bottom, in the corner
the unit must tilt towards that drain, if it does not, the condensate willl drip out of the door
into the pan.

the pan, is supposed to be dry, it is an emergency pan
blow the pan drain out from the unit to out doors

Typically, in most cases when it easily feasible, it drains out through a trap and then out of the attic and down to about 18" or so, above the ground where it is meant to drip out.
The drain pan you mentioned. Is that an open drain pan under the unit? Or a separate small pan?
Never heard of a branch of the drain being tied into the house system.

That's code!
I'm talking about what's typically done around here and what I've seen done at every installation I've ever seen.

EDIT: Have your experiences typically shown that it was done in accordance with that code?

it is perfectly acceptable to run a condensate drain to
either
lav y tail piece
over flow on a tub

i have done it a hundreds times

frodo said:

it is perfectly acceptable to run a condensate drain to
either
lav y tail piece
over flow on a tub

i have done it a hundreds times

Click to expand...

I always put a bucket under my drain line that typically drips to the ground. Then I use the water on my plants.

Diehard said:

I always put a bucket under my drain line that typically drips to the ground. Then I use the water on my plants.

Click to expand...

you are low tech..

get a water heater pan drain male adapter with the nut/washer
a 3/4 female adapter
a male x hose connection

drill hole in bucket , install fitting
hang bucket under leak,,route a hose out to your plants

lol

I'm retired. I can use the exercise.

Thanks all! I was going from memory, so I'll climb up to the attic and take a few pictures. The pan I'm talking about is a small pan between the unit and exit pipe that is dripping outside my eve. I think it's meant to catch water and direct it outside when the main drain is clogged, but like I said, I'll go make sure tonight.

Many people don't seem to know about the condensate lines connecting to the house plumbing to drain. Maybe it's a Texas thing. If you go online and search how to clean out condensate lines, you'll invariably find videos of people with drains dripping outside their house a couple of feet off the ground. That and adds for Gallo guns. No demos for my setup though. Thanks again.

you can find your drain by looking under the sink
if you see a rubber hose hooked to a y branch tail piece
that is the little bugger

or, look inside your washing machine drain box. if you see a 3/4 pvc pipe
thats it

i

if what Frodo and diehard is NOT the problem many pan clog were I work its usually 3/4 inch.....there are 2 things you can try home depot or lowes may rent a (kinetic ram)
high tech name for an air gun there are rubber attachments and there maybe a small plastic hose that fits on the end of the gun pump it up to about 20 psi rap a rag around it and pull the trigger.....you may get wet...….OR try a wet vac.....the gun has always worked for me......

bottom line

the pan is for emergency , it should not have water in it
if it does, solve that problem to solve the pan drain problem

properly piped condensate drain and pan drain

we had one in Riverside CA that was in the slab and drained into the back yard from the side of the slab where it exited. The dogs piled dirt up against it and we came home to wet floors one humid day. Anything from mud daubers, to algae, to debris can clog them.

Spiders clogged our condensate line, and ended up flooding two rooms. I called the home warranty service and they declined the claim saying it is up to the resident to make sure the drain lines were clear at all times. I ripped it all out, installed the A/C unit into the attic, ran the condensate line into an existing wet vent, placed a pan under it, and added an alarm into the pan so if it detects wetness, the alarm notifies us.

Yes, the last one I saw had a switch in the large pan under the entire unit in the attic. When it detected water in the pan, it shut the unit down.

Diehard said:

I'm retired. I can use the exercise.

Click to expand...

LOL

Kinda looks like my unit.

havasu said:

...and ended up flooding two rooms...

Click to expand...

@havasu - not sure how long ago this was but as an insurance claim; the repair of the unit (maintenance item) would not be covered but any resulting damage would have (should have) been covered. (example: pipe in wall freezes. rip out and pipe repair is not covered but any damage done would (should) be covered.)

As soon as you mention water intrusion to an insurance company, expect your rates to climb. This also carries over for the next 5 years, whether you own the house or not. I purchased this home in 2015, went to change insurance to AAA, to follow my cars, but was told the previous owner filed 2 water claims, and I was disqualified to bring my homeowners insurance to AAA for 5 years. I cleaned up the mess for about 8 hours labor, and did not get my insurance involved.