AC Water leak/poor cooling 2012 model 3700

[profcoyle]

We have a new 2012 Montana 3700 (3 months old) with dual ac. We generally like the unit but have an issue with the main ac. Our unit has 4 small round outlet registers and two rectangular air intakes located in the center of the 2nd ceiling panel near each sidewall. Montana eliminated the larger single air intake/outlet duct - which I believe was a big mistake. We previously owned a 2008 Everest 345S, which had the larger intake/outlet and never had any issues with cooling the living area. Additionally, during a couple periods of high humidity water formed on the ceiling below the main ac plenum, and water also ran down the inside of the ceiling and came out along the crown molding and side wall, damaging the crown molding. When it was 100+ outside the best the ac could do was to keep the inside between 90-95, even with the bedroom ac running. I've contacted Keystone about the problem but their suggestion is to take the unit back to the selling dealer (Nashville TN); we did have the selling dealer examine the problem and the only thing they did was to add a lot of aluminized duct tape inside the plenum. We are currently in Maine and are full-timing and not planning to be in the Nashville area in a long time, if ever.

[richfaa]

We have the 13 3402 with the same A/C arrangement.We have no problem with cooling the Rv. With temps in the very high 90's and high humidity we have no problem keeping the camper below 80

[DQDick]

We need to know more about what's going on. What fan speed are you using? Are your filters and rooftop condensing units clean? Is the air flow good to your registers? Are your drain holes in the AC pan clear ? That type of information. Then some of us can start giving you educated guesses of where to go next.

[profcoyle]

Will go up on the roof tomorrow am. Always run ac on manual, high fan speed, all doors and windows closed, get fair amount of runoff from roof, and also run bedrm ac.

[sreigle]

Profcoyle, something is definitely wrong. Your unit should still be in warranty. I might recommend you get it to a dealer and have him take a look and at the very least get the problem documented before you run out of warranty.

Ours is an older unit with the air intake in one location on the main ac and 5 or 6 ducts throughout the rig. Our front ac is not ducted. We've been running 100 to 106 or so day time highs for a month and between the two ac's have not had problems keeping the temperature below 80 and often lower. The thermostat on the main ac is at 77. The upstairs ac is on max cold and fan when it is running. We turn it on when the temperature downstairs hits about 79 or 80.

The seals should prevent that outside condensation getting inside the rig. And you should not be getting water inside. That makes me think the ac is icing up for some reason beyond my understanding.

Good luck with it. This is not a good time of year for ac problems.

[mhs4771]

X2 Rich's (richfaa) post. Although we have an SOB it has the same AC configuration and have been able to keep the inside temp in the low 70s while outside was in the mid to upper 90s.

[exav8tr]

I would suggest you call Keystone customer service and find a local, or close, dealer and call ahead, explain the problem, and make an appointment for repairs. This is what I did when we were fulltiming. We bought our rig in Anchorage, AK and left the state, for good, two weeks after we took delivery. We found by doing this, we never had a problem with getting repairs on the road. Try it, you'll like it. You definitely have a problem. We travelled the least coast a couple of years ago and it was 90+ for so long plus 80-90 percent humidity and my '06 3400 handles it very well. Inside temps were mid to high 70's.

[DQDick]

quote:Originally posted by exav8tr

I would suggest you call Keystone customer service and find a local, or close, dealer and call ahead, explain the problem, and make an appointment for repairs. This is what I did when we were fulltiming. We bought our rig in Anchorage, AK and left the state, for good, two weeks after we took delivery. We found by doing this, we never had a problem with getting repairs on the road. Try it, you'll like it. You definitely have a problem. We travelled the least coast a couple of years ago and it was 90+ for so long plus 80-90 percent humidity and my '06 3400 handles it very well. Inside temps were mid to high 70's.

X2. Keystone actually authorized a non-dealer to fix one of our issues in Deming, NM when no dealer was available. I sent in the bill, they sent a check right back.

[Ozz]

Sounds like it is icing up, low cooling and water damage. I agree about the smaller ducts in the return. I haven't seen them, or measured them, but even if they are the same sq ft with the 90 degree turns, that restricts airflow, can you get to the evaporator (cold) coil? If so, see if it is icing. The small sensor may need to be moved, or re-attached. It keeps the coil clear of ice. A low refrigerant charge is a possibility, but I would think airflow first. But if it ices up all the time, you will have a lot of time the compressor isn't running, that will cause warm room temperatures as well. Obviously..
Can you hear if the compressor cycles off? A bad wall thermostat is a distant possibility, but you would hear the compressor cycling off. Good luck. Ozz

[Dontana]

Bill, Sorry you are having this problem. We also have a new 3700 '12, but we have the "other" setup, with no vents on the ceiling outside of the main unit. It probably won't make you feel any better, but our dual AC arrangement does okay in the warmer temps. I hope that you get things taken care of soon. Good luck.

[Carl n Susan]

I didn't realize (and I suspect I am not alone) the major change Montana has made to the A/C system. By mounting return air ducts on the side and eliminating the hole in the ceiling, there is no way to see or correct a leak until it is too late (water in the crown molding and down the walls). I assume this is a much quieter system but I am not sure I like the loss of the dump valve.For those who have had problems with freezing of the coils, how do check for it without an access point?

[Mntnlife]

Regarding the poor cooling, sounds like you are having the same problem with a restriction in the return air part of the system. Many posters have been complaining about not being able to sufficiently cooling the living room portion of their trailers. From what I have read, during construction of the trailer and with a slight arch at the edges of the ceiling, Montana uses a rigid rectangle duct coming from the intake to the a/c unit. When the worker installs the duct he/she attaches one end and then fold the duct down. this causes the center of the duct to collapse and therefore restricts the airflow in the area. Pull the intake vent grill and if you can, use a cell phone camera to take a picture of the inside of the duct. Look to see if it is collapsed. I have heard of some people taking 2" pvc and propping open the duct and this also allows air to flow through the pvc.

Hope this helps.
Tim

[Irlpguy]

It would appear your rear AC intakes are the same as on my 2012 - 3402RL and this is what both vents looked like before it was "fixed" at the dealer.
Although there is more open space now than before it is a poor/restrictive means of getting sufficient air into the AC.

Take off the two side vents and use a mirror and flashlight to check on your vents, then as was suggested and as I did take the picture with a cell phone camera.

Contact Keystone to register the problem and see if they will suggest a Keystone repair facility near your location. If not ask to have it done by a non Keystone dealer.

This engineering marvel may have quieted down the AC but it sure does not work nearly as well as the old system.

Good luck in the solving the problem and getting a resolution..