roof leak through rear ac return air duct

[Phabask]

When it rains I get water in my return air ducts on my rear a\c I have a 3700 RL, replaced rear A\C last year, installed a new Dometic blizzard, the original was Brisk 2, I have replaced the seal twice, I get more moisture on the left side than the right, there is not alot of sign of moisture at the main trunk,

[dieselguy]

I read thru this last year ... sounds like it could be your issue.
http://www.keystoneforums.com/forums...d.php?p=217768

[phillyg]

Had/have the same problem. Repaired under warranty at LD Tampa. They "fixed" and put it in their wet bay; no leaks. We've had very little rain in SWFL since but the one time it did, we were in it and got some drips do it's not totally fixed. It's not a leak from the AC/roof primary seal. Rather, it's coming through the AC somehow and the techs dont know how to properly repair it. Stay on them because water ingress will be a serious problem thru the years.

[belldog]

I am having leak problems also. Taken it back to dealer for repair but each time I get water in return air duct. Am waiting on Northgate Rv in Ringgold Ga to get back on problem. Will let you know if they find the problem.

[Bad Moon]

Had this same problem on my HC. Took two sessions with the dealer to get it fixed under warranty. I had to figure it out for them. There is a series of bolts inside the AC housing. One was missing from the factory. They installed a new bolt and nut and gooped it up with silicone. So far so good. My only concern is long-term damage to the ceiling. I still keep the AC covered when it is stored, because I don't completely trust it.

[dieselguy]

So ............ did anyone after looking at the photos in the link to the Keystone Forum from my earlier reply .... pop the bonnet off and try the silicone sealer on the riv-nuts and in the pocket area of the return side of the A/C housing? I'm just curious about any success. It appears the Blizzard model is prone to leaking water.

[phillyg]

My 3711FL is back in for warranty service for this and a couple other minor issues. I've noted your posts and will copy your fix if the dealership fails again.

[jameswbarton]

I used to use Countryside RV in Ringold. They are to notch! I got really burned bad by RV007 in Danville.

[belldog]

Carried Montana to dealer they put eqpt to put pressure on a/c found leak sealed. But first rain had water in duct. Emailed dometic about problem about week ago no reply from them.

[Phil P]

Hi

There are 2 attic ventilation fixtures on the roof of our 3665RE that had deteriorated from the sun and caused what we thought was an AC condensate leak.

On ours it was easy to see the rear one standing on the ladder at the back of the trailer.

Had both replaced and that fixed the leak.

Phil P

[bowlesj]

Originally Posted by dieselguy

So ............ did anyone after looking at the photos in the link to the Keystone Forum from my earlier reply .... pop the bonnet off and try the silicone sealer on the riv-nuts and in the pocket area of the return side of the A/C housing? I'm just curious about any success. It appears the Blizzard model is prone to leaking water.

That was me that posted that fix on Keystone and this site. Still fixing these as they come through our park. They must be repaired as I noted in the post. Just putting a bolt in the rivnut and sealing will still allow water around the lower part of the rivnut to leak into the return air duct.

And yes, this does sound like the original poster's problem and dealers still don't seem to be able to figure it out completely.


John B - 3820FK

[merc1118]

I have copied an e-mail to Curtis Trailers in Portland about this issue with my 3160RL:


At Your Service Mobile RV Service came by on Friday morning to repair the water leak in the drivers side air return duct, rear air conditioner on my 3160RL. They were sure that the fix would be installation of a new main seal. Once the shroud and styrofoam inner cover were removed, the technician checked the existing main seal and determined that it was tight and in good condition. I had the Heartland Service Bulletin you sent me and showed it to the technician. We checked for signs of water infiltration into the pan and subsequently into the return air duct. There was a water scum line in the front drivers side corner of the pan and it could be seen that water was coming in from the drivers side corner of the shroud through a significant opening in the junction of the shroud and pan on the front drivers side corner. Additionally there were two unsealed holes in the floor of the pan inside of the main seal area and directly over the air return ducts.These holes are noted in the Heartland service bulletin and the technician sealed them on the top and underneath where they opened up into the return air duct. The technician also drilled all of the 1/4" and 1/2" holes in the pan where indicated in the service bulletin and installed the top shroud back on the unit.

A coulple of things to note:

The front passengers side shroud screw was crossthreaded and the technician had to drill it out which obviously made the screw unusable and left the shroud unsecured at that corner when he was done. I purchased some stainless 5mm screws and washers from Ace Hardware and was able to fix this problem. The last person to install the shroud was a technician at Curtis. I assume that he used a power screw driver to install it. I recommend using a manual screw driver rather than a power driver to install these screws so the problem won't occur.

I did a fair amount of research on this issue in the RV forums and have provided a link to a post in the Montana Owners Forum that addresses this problem with a fix that incorporates the Heartland service bulletin along with installation of Gorilla tape over the seam between the shroud and pan. http://www.keystoneforums.com/forums...d.php?p=217768

So, at this time all of the steps in the Heartland service bulletin, sealing the holes directly over the return air duct, drilling holes in the pan, and installation of Gorilla tape have been completed. I feel fairly certain that this will resolve the problem, but as they say: "The proof is in the pudding."

I think the Curtis should advise Keystone of my specific issue and that Keystone should work with Dometic to come up with a positive resolution to the problem. Dometic has poorly engineered this air conditioner and should take appropriate action by acknowledging that there is a problem with their unit and coming up with a real fix that includes replacement of the shroud and pan and a method to deflect water away from the return air ducts. Maybe Dometic should do a complete recall on there air conditioners and replace them with units that actually work properly and don't leak. I can't help but think about all of the Montana owners who store their units outdoors over the winter and are going to find or have already found a big mess when they start to get ready for the new season.

[merc1118]

Since the repair on my unit in the previous post, after 30 minutes of hard rain, there has been no water leakage. I mentioned the Heartland Service Bulletin in my previous post and failed to attach it - it is attached to this post. So far, it appears that the Heartland fix has resolved the issue along with Gorilla tape application around the front and sides of the shroud and pan seam. I will not be completely satisfied with the resolution until a sustained period of heavy rain.

The Service Bulletin doesn't say anything about using Gorilla tape on the shroud/pan, but it is mentioned in the post that I provided a link to in my previous post. Dometic's junction between the shroud and pan is terrible and in my case, I am sure was "one" of the main reasons there was a leak. The front driver's side junction had a gap of about 1/2", a significant space for water penetration during heavy rain. It is unfortunate that this design flaw requires application of Gorilla tape to fix a water penetration issue on a relatively new piece of equipment. I will be following up with my dealer and Keystone regarding this issue and the poor engineering of the Dometic AC.

I hope this information helps other Montana owners having the same problem.

merc1118
2017 3160RL
2012 Chevrolet Suburban 3500 Duramax

[Butch & Kathy]

Thanks for a copy of the service bulletin. I have performed all of the steps to seal the holes but not the drilling of new holes. I will add that to my list of things to do....

[Mister.anderson]

I have a 2016 3711FL, I completed the service bulletin last year and has began leaking now. For sure the problem is the gap in the shroud I think over time of UV exposure it shrinks at different rates and began to leak. I sealed mine with window tape and I hope that does the trick. Thanks for the great advice, since the dealer is useless. Did you have any luck with the manufacturer regarding this? I will be doing the same.

[Bad Moon]

Good luck getting Keystone to do anything. Customer service after the sale is not a priority with them.

[bowlesj]

Originally Posted by Mister.anderson

I have a 2016 3711FL, I completed the service bulletin last year and has began leaking now. For sure the problem is the gap in the shroud I think over time of UV exposure it shrinks at different rates and began to leak. I sealed mine with window tape and I hope that does the trick. Thanks for the great advice, since the dealer is useless. Did you have any luck with the manufacturer regarding this? I will be doing the same.

It is VERY important to not only accomplish the service bulletin (of which the drilling extra holes is not required and definitely not recommended by me) but to accomplish the additional sealing inside the return air duct at the exit of the rivnuts noted. All this information is in the post merc1118 links above. My tests show when properly done as I specified in that post the shroud taping isn't required. I just did it as a precautionary measure. We have had ZERO leaks since including during Hurricane Harvey.

Good Luck


John

2016 3820FK

[merc1118]

My 3160rl was parked next to my house in Oregon after doing the Heartland fix and applying the gorilla tape. No leaking at all occurred after a lot of rain, snow and ice.

Last week I decided to go up and take a look at it. The tape was still holding, but I thought it was time for replacing it. Bought some of that flexible rubber tape "as seen on TV". You know the stuff, in the TV ad the guy cuts the aluminum boat in half and tapes it back together. Bought a 10' foot roll of it, removed the old gorilla tape, cleaned up the residue with acetone and applied the new tape. It's 5" wide and does a better job than the gorilla tape. In my case, the shroud had a very large gap that I am sure contributed to the leak.

It's probably good for at least another year.

[bowlesj]

Only thing is that flexseal and eternabond tape is a pain to remove when accessing the a/c unit. Otherwise very waterproof.

John
3820fk

[merc1118]

You're right about removing the flexsteel tape. At this point I will probably replace the unit before there's a need to replace the tape.

The trailer has been working pretty well for the last several months. We've been full timing since September with no issues. The first two months in Arizona with multiple 90-100 degree days. We did need to switch the AC fans to High and run both ACs on the really hot days. Switching fans to High keeps the ACs on full time while cooling. Future plans for cooling are vent pillow covers in the overhead vents (the kind that has foil on one side that holds down condensation), foil on the sunny side windows, foil over the shower skylight and covers on the stair risers to keep the cool air in the trailer and not vent it to the basement.