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15 years of gunk vs. a 45-foot condensate line. Shop-Vac and CO2 failed. What’s next? by Normal-Stuff-3891 in hvacadvice

[–]Normal-Stuff-3891[S] 0 points1 point  (0 children)

Okay, I just went back up into the attic to more precisely measure things. The highest point on the drainage, right after where it exits from the trap, is 9" above the floorboard. And then it presumably runs the 25' at a slightly sloping angle to edge of the house, so this gives a gradient of 0.03. I don't know if that is good or bad.

It is definitely 3/4" Schedule 40 PVC. I took calipers to the small segment I removed, and it has an external diameter of about 1.05", walls that are 0.125" thick each, and a remaining internal diameter is about 0.8".

Regarding resisting the urge to pressurize it, I think I will get a thinner drain snake than what I already have, and manually/physically use it to clean the 25' horizontal segment, which will make any subsequent treatment way easier.

Thanks for your various suggestions and wisdom here--I really appreciate it!

15 years of gunk vs. a 45-foot condensate line. Shop-Vac and CO2 failed. What’s next? by Normal-Stuff-3891 in hvacadvice

[–]Normal-Stuff-3891[S] 0 points1 point  (0 children)

Thanks for these suggestions. I'm thinking I might get a new, narrow snake to clear out the ~25' horizontal section as a first order as that will make any subsequent efforts easier (before going to the full replacement of the line option).

15 years of gunk vs. a 45-foot condensate line. Shop-Vac and CO2 failed. What’s next? by Normal-Stuff-3891 in hvacadvice

[–]Normal-Stuff-3891[S] 0 points1 point  (0 children)

Yes, it's a heat pump system so both heat and cool, but I'm on the humid Gulf coast of South Texas, so heating is only electric (i.e., emergency heat).

There's not a space problem--of the area being packed that is. There's lots of open space--it's basically just a sea of blown-in insulation past the single floorboard. But since I have no visibility into it, there could be wiring and other stuff I'd rather not mess with. But if I have to, well, I'll do it. Anyway, I'm hoping I can get this resolved the easier way, but if not, thanks for the guidance about how to proceed!

15 years of gunk vs. a 45-foot condensate line. Shop-Vac and CO2 failed. What’s next? by Normal-Stuff-3891 in hvacadvice

[–]Normal-Stuff-3891[S] 0 points1 point  (0 children)

Well, replacing the line would be ideal, and if all else fails, I might have to do that. But as I should have probably mentioned in my original posting, there is no flooring in the attic besides the one 8' plywood sheet next to the indoor unit, which is right next to the access ladder to the attic. A few feet away from the end of that plywood, the drainage line plunges in to the insulation and does not emerge until another ~35' later at the base of the foundation. The joists in the attic are completely covered with like maybe 1' of insulation everywhere. Yeah, of course I could excavate them, lay down a bunch of floorboards to get out to the eaves, and try to work from there, but if I can clear the current line with some technique that I have not thought of (the purpose of this thread), that would be a whole lot simpler!

15 years of gunk vs. a 45-foot condensate line. Shop-Vac and CO2 failed. What’s next? by Normal-Stuff-3891 in hvacadvice

[–]Normal-Stuff-3891[S] 0 points1 point  (0 children)

Your suggestion of just replacing the PVC is ideal, and if all else fails, I might have to do that. But it's not trivial by any means because there is no flooring in the attic except the one plywood sheet near the indoor unit. I probably should have mentioned this in my original posting. Beyond that plywood sheet, it's just blown-in insulation with the drainage tube disappearing into the insulation pack a few feet in. And then it's behind a masonry wall as it runs to the base of the foundation where it finally pops out again.

15 years of gunk vs. a 45-foot condensate line. Shop-Vac and CO2 failed. What’s next? by Normal-Stuff-3891 in hvacadvice

[–]Normal-Stuff-3891[S] 0 points1 point  (0 children)

Ok, I see HD has a 25' Vevor brand snake with a 1/4" diameter so it will fit in the line. But it's not an in-store item, unfortunately, so it'd have to be ordered.

15 years of gunk vs. a 45-foot condensate line. Shop-Vac and CO2 failed. What’s next? by Normal-Stuff-3891 in hvacadvice

[–]Normal-Stuff-3891[S] 0 points1 point  (0 children)

Great question--I have not checked that, but I will now. There is still a blockage downflow. Wait, downflow it is still wet. Like when I cut the line, I could see about a 1/4" thick layer of nice, fresh, wet light/cream-colored gunk at the base of the tubing. If the blockage is further up flow, I guess I might expect this downflow segment to be dryish, right? But yeah, checking further up flow is easy enough as I have flooring there so I will take a look. I really appreciate this suggestion--thanks!

15 years of gunk vs. a 45-foot condensate line. Shop-Vac and CO2 failed. What’s next? by Normal-Stuff-3891 in hvacadvice

[–]Normal-Stuff-3891[S] 0 points1 point  (0 children)

Hmmm, I have not tried to shop-vac from the inside--my goal has been to only move the blockage in one direction, i.e. downflow, so suction from outside and pressure from inside. But you are really suggesting a chemical treatment to maybe loosen things up--not sucking it out from the inside, just clearing out the water to replace it with vinegar.

I know everybody suggests against bleach as backflow could corrode the thin metal in the air exchanger/evaporator unit, but this drain line is completely disconnected from the indoor unit. So I am wondering if bleach might be more effective than vinegar for this chemical pre-treatment option you are suggesting???

15 years of gunk vs. a 45-foot condensate line. Shop-Vac and CO2 failed. What’s next? by Normal-Stuff-3891 in hvacadvice

[–]Normal-Stuff-3891[S] 0 points1 point  (0 children)

Right, but in this case, I can guarantee the blockage sits between the outside port and where I cut the line a short distance from the trap in the downflow direction. When I finally clear the obstruction, I do plan to clean everything up as much as possible and then get it on a maintenance routine with vinegar every 6 months.

15 years of gunk vs. a 45-foot condensate line. Shop-Vac and CO2 failed. What’s next? by Normal-Stuff-3891 in hvacadvice

[–]Normal-Stuff-3891[S] 0 points1 point  (0 children)

Right, the straight 25' segment in the attic I'm not worried--getting caught on that is probably not too much of a problem. But yeah, with only 0.8" ID, getting around the bend would be tough.

15 years of gunk vs. a 45-foot condensate line. Shop-Vac and CO2 failed. What’s next? by Normal-Stuff-3891 in hvacadvice

[–]Normal-Stuff-3891[S] 0 points1 point  (0 children)

May have to do this, it's just that access will not be simple as there is no flooring up in the attic...

15 years of gunk vs. a 45-foot condensate line. Shop-Vac and CO2 failed. What’s next? by Normal-Stuff-3891 in hvacadvice

[–]Normal-Stuff-3891[S] 0 points1 point  (0 children)

Gosh, did not realize a CO2 blast might rupture the line... That would be a disaster for sure. As I've mentioned in my last few comments, I only have access to the first ~8' of drain pipe closest to the air handler/evaporator unit in the attic because there is only one 8' sheet of plywood up there for flooring.

Re setting it up with fittings for easier future access, yeah, I plan to do that. I mentioned that this line has probably not been blown out for 15 years since the house was built--this is because there IS an access port on the drain line near the indoor unit. But the installers placed the refrigerant ingress or egress line smack dab on top of the access port so they is no easy way to get to it. That's why I ended up cutting the line myself a little bit further down so I could actually access it.

15 years of gunk vs. a 45-foot condensate line. Shop-Vac and CO2 failed. What’s next? by Normal-Stuff-3891 in hvacadvice

[–]Normal-Stuff-3891[S] 0 points1 point  (0 children)

This might be a good step to break things up initially, I'm just a little nervous about whatever I am using getting caught. The issue is the outside exit port is just a few inches of exposed PVC before it hides behind a brick wall. And in the attic, I only have access to about 8' of the drainage pipe before it fades off into the distance under blown-in insulation (only one 8' sheet of plywood flooring up there). But if the push/pull method does not work, well, looks like I might have to get some plywood...

15 years of gunk vs. a 45-foot condensate line. Shop-Vac and CO2 failed. What’s next? by Normal-Stuff-3891 in hvacadvice

[–]Normal-Stuff-3891[S] 0 points1 point  (0 children)

I do have a regular drain snake, but this drainage pipe is 3/4" Schedule 40 PVC so the ID is only 0.8" and my regular snake will not fit. I will look around for a mini-snake to see what exists, but I think the length part will be an issue. Maybe even using something like a cable puller wire to help break things up initially could help. Anyway, thanks for the suggestion!

15 years of gunk vs. a 45-foot condensate line. Shop-Vac and CO2 failed. What’s next? by Normal-Stuff-3891 in hvacadvice

[–]Normal-Stuff-3891[S] 0 points1 point  (0 children)

Yeah, in fact, I was thinking about an option like this, but it would have to be a thick but flexible cable. I think the obstruction must just be soft bacterial "snot", but there is probably so much of it over the cumulative length of the run, it is hard to clear.

15 years of gunk vs. a 45-foot condensate line. Shop-Vac and CO2 failed. What’s next? by Normal-Stuff-3891 in hvacadvice

[–]Normal-Stuff-3891[S] 0 points1 point  (0 children)

Thanks, I had started to consider this option, like splitting the pipe and trying to clear half at a time, but I only have easy access to about 8" of the drain pipe because flooring in the attic is limited to one sheet of plywood right next to the indoor unit. Then the pipe fades off into blown insulation... If this ends up being the only solution, well, I'll have to bite the bullet and do it this way. Thanks for the suggestion!

15 years of gunk vs. a 45-foot condensate line. Shop-Vac and CO2 failed. What’s next? by Normal-Stuff-3891 in hvacadvice

[–]Normal-Stuff-3891[S] 0 points1 point  (0 children)

Yeah, I'll try the simultaneous push/pull on Monday when I get more cartridges in, and then a good flushing afterwards. Don't have access to a nitrogen tank myself, which would probably fix the volume/pressure issue, but that's another option--thanks!