Condensate drain lines

[gjh2916]

Has anyone ever cleaned the tubing for the condensate drains on the rooftop AC units? looking for the best method, under heavy usage my front AC unit starts dumping condensate on the roof and it never use too. I have had the cover off the unit and the evaporator tray hole is clear, I am assuming there is blockage in the tubing leading to the bottom of the coach. tried blowing it out with compressed air to no avail. Any advise would be appreciated.

[Russ R]

I blow mine out with air once a year. I do it from inside the coach. I can access mine from inside when I pull down the AC covers. I remove the hose clamp and blow air through.

[Ivan K]

Combination of compressed air and suction with a shopvac might work. I tried a stiff wire from underneath but my blockage was past an elbow. Being on the road, I pumped vinegar and then draino in it but eventually had to disconnect the flexible line from pan to pex and blow it out from there, from inside ceiling opening. Careful with the pressure setting, would not want to blow out elbow fittings up there in the ceiling.

[96 EVO]

Vinegar is what I was thinking as well, but haven't needed to try it.

Maybe plug the drains at the bottom, pour the vinegar from the top, and let it sit a few hours.

[vito.a]

Usually, it's best to blow them out backwards, from the ground up.  You have to find where they dump.  Usually by the front wheel well and in the back of the engine compartment.  

My front drain lines were burned where they pass behind the refrigerator.  

Edited September 14 by vito.a

[Doug and Nicki]

I put the garden host to the bottom of the tube using a controllable nozzle. Shoot water into the tube for a brief second. See what comes out after you stop. I had a lot of black stuff come out. Not sure what it was. After doing this few times, it will run clear. Thak took care of it for me.

[jacwjames]

The small drain cups mounted on the bottom of the AC is where the blockage might be, but almost impossible to clean out.  I had stink bugs in mine when I replaced the AC's. 

I have used compressed air from the inside to blow mine out.  I take the tubing loose from the T and blow in all directions. 

Edited September 14 by jacwjames

[Steve P]

Kinda makes me glad I don't have condensate drain lines, although I would appreciate not having to re-caulk gutters so often, and replace drip spouts... cement fails or tree branches knock them off.

[96 EVO]

13 minutes ago, Steve P said:

Kinda makes me glad I don't have condensate drain lines, although I would appreciate not having to re-caulk gutters so often, and replace drip spouts... cement fails or tree branches knock them off.

Ha, no they are worth having.

Mine are all still flowing after 17yrs.

When I'm washing the roof I give a little blast of water into the collection cups.

[Dr4Film]

Dirt Dubbers are notorious for clogging up those drain lines. I installed screens on the output of those two drain lines on my previous 02 Windsor. I have also done it to my 06 Dynasty. Never had any clogging of the drain lines.

[Garry Donohue]

I used my shop vac attached to the bottom (exit side of tube), then I disconnected the “T” up top from the inside, then turned on vac and went inside and covered the hole with my thumb intermittently. Then opened shop vac to see what came out. So empty the vac before doing this do you can see what you caught. 

[woodylmiller]

I am in the process of troubleshooting my A/C units.  Looking at the drain line from inside, since I have all the returns opened up, I see a nice kink in the middle unit where someone didn't think a little kink in the drain line would matter.  So I'll need to fix that little problem.  Anyway, make sure that someone during care about how they tied up the drain lines.

Woody Miller

09 Dynasty

[Floyd4949]

Has anyone tried .095" string trimmer line?
I've had success using it on automobile sunroof drain lines on my Mini Cooper.

[gjh2916]

On 9/16/2024 at 6:03 AM, Floyd4949 said:

Has anyone tried .095" string trimmer line?
I've had success using it on automobile sunroof drain lines on my Mini Cooper.

Used trimmer line from the top down and all kinds of black stuff came out bottom. Only time will tell if this corrected the problem but I am sure it will. Thanks everyone for your responses.

[LakeBob]

I've used the compressed air method with success, disconnecting  the inside connection behind the filters and blowing both ways.  Definately blew out a blockage on my problem unit.   I also had to reposition the drain line on my center AC as it was kinked during installation and effectively blocked the flow by 75% or more.   

I read a tip once that pouring a 25% bleach/water solution into the drain cups would help break up mold that grows in the lines, especially in warm and humid climates.  I did this to all mine when I purchased, as it was a Florida based coach. 

[lake49068]

One of my discharge lines was not flowing...pulled inside AC cover, disconnected line and gave it a shot of LOW pressure air.  Also found that the little screen that doubles as a faucet gasket for a garden hose is a press fit for the discharge line and it keeps the daubers out.