A/C condensate running off the roof... NOT out of the drain tube

[Hiho Silver]

Originally Posted by GammaDog

HiHo: Do you know where the kink in your drain is? I had one confirmed and two more suspected. The confirmed was where the single 1/2" clear plastic line between the tee fitting and the wheel well exited the 14" square frame that forms the hole in the roof. Under no circumstance would I have attempted to fix that with a sleeve within the tube. It probably would have kinked as well. I took the easy route and that was to extend the single tube at the tee by an inch or two to relieve the strain that caused the kink.

The other two areas that I believe were kinked (or maybe "compressed" or "piniched" would be better terms) were where the tubes from each cup passed through the gasket. I still think the additional gasket is the way to go (Dometic suggests cutting 3/4" of the upper gasket on each side to accommodate the tubes. The factory Airstream gasket on my trailer was not cut through, it had been grooved.) If you really, really wanted to sleeve those two sections I would consider a 2" length of either brass or stainless tubing. I would not use smaller clear plastic tubing within the 1/2" clear plastic for two reasons: 1. The sleeve would compress as easily as the factory material and 2. Clear plastic tubing is relatively thick walled. A metal tubing sleeve would leave a much larger opening than plastic.

Yes, it is obvious to me that the 2nd gasket is needed. For that job I need to hire someone else, its not something I can do myself.
I don't want to "really, really sleeve" the drain hose, just reporting what Airstream suggested. (I have a ducted air model with drain hoses accessible inside the trailer.) I think my problem is that the drain hose is flattened (compressed) between the cup and the tee, (the cup on the street side with the shorter hose). I blew compressed air thru it, but I don't think it helped. I tried to run a wire thru the hose, and not sure, but seems like it doesn't go far enough before hitting an obstruction. Anyway, I have a guy coming to my place tomorrow to install some easy starts and I am debating with myself rather or not to ask him to pull the a/c unit for an inspection. I don't want to compromise any seal that is keeping the water away from the inside of our trailer. Is there a sealant someone could recommend that would be readily available like at Home Depot. I think I've read that some guys use sikaflex 221 as a sealant, wish I had some one hand. I do have some Adseal on hand but it is old, probably not usable. Thanks again for everyones help,
Sandy

[RFP]

Originally Posted by Hiho Silver

< snip > I don't want to compromise any seal that is keeping the water away from the inside of our trailer. Is there a sealant someone could recommend that would be readily available like at Home Depot. I think I've read that some guys use sikaflex 221 as a sealant, wish I had some one hand. I do have some Adseal on hand but it is old, probably not usable. Thanks again for everyones help,
Sandy

Good morning, HHSilver, and a delightful Saturday to you!

You should have no worries about the sealing of the air conditioner to the roof. The gaskets do all the sealing... there is no other 'sealant' used or needed. The Dometic gasket is wide and has the right compliance to do a great seal all by itself. Again, no other sealant needed.

[Hiho Silver]

Originally Posted by RFP

Good morning, HHSilver, and a delightful Saturday to you!

You should have no worries about the sealing of the air conditioner to the roof. The gaskets do all the sealing... there is no other 'sealant' used or needed. The Dometic gasket is wide and has the right compliance to do a great seal all by itself. Again, no other sealant needed.

Robert,
Well, you have done it and I appreciate your advice, and thanks again for all your great posts. In the directions that I think you posted item #5 says "Seal below and above each drain tube where it goes through the roof gasket with a good all weather sealant." That is what I am referring to. Did you do this per dometic's instructions, or did you find it unnecessary? Anyway I guess most any good sealant could work.
Thanks Sandy

[rperrym]

To Hiho Silver:
you said in your post you had a ducted air model and the hoses are accessible inside. How do you access them?
Thanks,

Rick

[A W Warn]

Originally Posted by Hiho Silver

Robert,
Well, you have done it and I appreciate your advice, and thanks again for all your great posts. In the directions that I think you posted item #5 says "Seal below and above each drain tube where it goes through the roof gasket with a good all weather sealant." That is what I am referring to. Did you do this per dometic's instructions, or did you find it unnecessary? Anyway I guess most any good sealant could work.
Thanks Sandy

You will need the sealant around the pipe where it penetrates the gaskets.
Since this is not on the skin, any caulking that stays flexible will work. However, I would chose polyurethane caulk same as I use around windows and doors. (options: Tremco 635, Sika 221, Lexel, Tremco Vulkem 116, gutter seal)

Originally Posted by rperrym

To Hiho Silver:
you said in your post you had a ducted air model and the hoses are accessible inside. How do you access them?
Thanks,

Rick

Return air vents
Photo and explanation a few post above. (103 & 110)

[jmpgino]

You have a lot of work to do before you lift the AC off. It’s not so simple......
If you remove the ceiling covers inside the Airstream you will see everything, including what your problem is.
And if you do not use Sikaflex, well be it on your own head.
Two of us have given enough information for anyone to easily tackle this problem.
It’s time to read up here, then plan how you are going to attack the problem.

[A W Warn]

The first post in this thread has 3 photos, as well as instruction.
Basically all the information anyone needs to know to do the install. (Thanks Lewster)
http://www.airforums.com/forums/f44/...ml#post1299898
This thread is from 5+ years ago, I think where I first learned of the drain cups.

[RFP]

Originally Posted by Hiho Silver

Robert,
Well, you have done it and I appreciate your advice, and thanks again for all your great posts. In the directions that I think you posted item #5 says "Seal below and above each drain tube where it goes through the roof gasket with a good all weather sealant." That is what I am referring to. Did you do this per dometic's instructions, or did you find it unnecessary? Anyway I guess most any good sealant could work.
Thanks Sandy

Sorry, Sandy, for the delayed response (Son visiting from Portland!). Yes, the installer used some kind of gray-pookey around the hoses where they penetrate the gasket.

But it's 110-degrees here right now, and it's NEVER going to rain here again anyway, so it probably doesn't matter
C'mon Colorado trip!

[jmpgino]

Well over the weekend I decided to check the unit before I finally bolt and torque her down onto the roof, she has been just sitting for a good five or six weeks now.
The drain lines are a good 50% compressed with just the weight of the AC unit and I bet the heat here down in Georgia is adding to the problem. So torquing this unit down as per Dometic instructions is going to make this constriction even worse.
Anyone considering attacking the replacement of an AC unit should place......

TWO METAL SLEEVES WHERE THE DRAIN LINES GO THROUGH THE GASKETS

......I can not emphasize this point strongly enough. If you do not add this easy step in your installation, you are asking for trouble down the road.
I also added an L connecter into the AC drain return line, the pipe sweep method Dometic is instructing is flawed. My pipe had constricted nearly shut, so I put the L connecter in after the T Dometic supplied and the line now runs straight to the exit drain line.
Another issue I had banging around in my head was with the electrical box. It is so big that it has to be stuffed up into the return air box for you to attach the base plate on the ceiling. This seriously constricts the airflow a good 40% so after a good deal of mulling it over I decided to not use it and went this way....
I Soldered all of the wire connections, then sealed each wire nut full with a hot glue gun. Then zip tied the wires together like a sausage and placed a plastic bag over them and taped it tight.
Then they can hang up on the side of the return box, bag bottom facing downwards and they now take up very little of the box.
Cutting the excess wires is also needed because for example the Airstream power supply line was a good three feet in length, so I cut it back to about 18 inches. Also the Dometic AC wires are in need of cutting back as well. These wires if not cut to the correct length will bunch up and compress the drain lines from below, when the bottom plate is tightened.
I am going to tighten the bolts by hand now and not torque them down, once I see the gaskets being compressed from below, I will just give them another turn. So that’s it, finished.

[Bgibbs]

As my last effort to stop the condensation on the roof, I wrapped the suction lines with cork insulation tape to stop the sweating.

[Endl]

Guys I just added the drain cups to a 2005 unit and found all of the problems you guys described.
1. Drain cup kit only came with one gasket, which when compressed was going to squish the drain tubes and or break the cups over time.
My remedy was to make a second gasket from Owens Corning hard foam insulation. I had to it was the weekend. These gaskets are cheap and at some point in the future I will replace with the made gasket but it actually worked well "other than its blue lol" I placed the black gasket not pictured over the blue made gasket since it was going to contact the roof and would provide the seal.
2. when you connect the hoses and Tee it causes the flexible wall OEM drain tubing to compress and kink up and water may pass through this but will definitely cause problems in the future. Remedy was to add a 1/2 inch barb elbow between T fitting and OEM AS drain tube. Also if adding this kit to an older unit it helps to leave the clamps off until you get all the tubes lined up correctly so you don't have any kinks in the drain tubes.

I added some pics to show some of the process and how the cups are connected.

[GammaDog]

Looks good Endl! I like the idea of a 1/2" barbed elbow to make the turn in the drain line. I actually ordered one and have it in reserve but it had not arrived before the reinstallation. Even slight tension on 1/2 " clear plastic drain line as it bends will cause a kink... and we all know what kinks in the drain line cause!

[369goose]

Our ‘14 FC AC occasionally drips onto the floor INSIDE the Airstream while flowing thru drain tube to the outside.

Suggestions?

[n2916s]

If you have a compressor, you might shoot a little, low pressure air back up the tube as you might have a partial blockage.

[Jim Flower]

I added a little funnel and hose at the discharge so I could blow air into the whole mess. Also ensure that filters are clean so as not to encourage condensation build up.

[GMFL]

Originally Posted by 369goose

Our ‘14 FC AC occasionally drips onto the floor INSIDE the Airstream while flowing thru drain tube to the outside.

Suggestions?

Goose,
The problem is not that you’re drain Tube is clogged. I have the same problem. Where the air intake is located there is a pan inside the AC unit, this pan can hold water. When the air-conditioner sucks air in It can pull some of that water up. The water then Collects on the inside wiring and drips down. You can remove the inside air distribution box and reposition the wiring with a few zip ties and that may solve your problem

[Foiled Again]

Dripping inside seems to happen in very high humidity when you might be trying to over-cool the interior... or by accident leave a fan cover open and make it impossible for the a/c to ever reduce the humidity. I use a plastic ketchup squeeze bottle, jamming the nozzle up the drain tube and sucking the water out, rather than blowing it UP. Have pulled some nasty looking gunk out, then it runs like mad for weeks or months.

Side note: anyone with heart or breathing problems may be subject to fainting if they abruptly go from a very cold room to an outside temp that is 20°F hotter. I just got my upgraded 15K unit installed and it is a meat locker in here! ( Bragging, not complaining) I am backing off the cooling by about 3 degrees.

[Jim Flower]

Originally Posted by Foiled Again

I use a plastic ketchup squeeze bottle, jamming the nozzle up the drain tube and sucking the water out, rather than blowing it UP.

Great hint. It will save me from myself. Jim

[HiHoAgRV]

Originally Posted by Foiled Again

... I use a plastic ketchup squeeze bottle, jamming the nozzle up the drain tube and sucking the water out, rather than blowing it UP.. .

I bet that makes the French fries taste funny.

[Foiled Again]

Originally Posted by HiHoAgRV

I bet that makes the French fries taste funny.

[emoji849][emoji849][emoji849] I use it for the drain tube and to.put a bit of bleach in the white tank. Might squirt some Calgon in there too. Soft water to clean the aerators and shower nozzle. Will skip the detergent for obvious reasons. I do use bottled water for drinking at many campgrounds (BUY by the gallon, and rebottle good local water when found. Do wish paper carton water could be found locally.)