Suburban Furnace Issue

I purchased a 2016 Rockwood 2506S travel trailer last year from Santa Rosa/Fairfield RV Sales in California. At no time was I told during the sale of the trailer or during the walk-thru where they instruct you on how everything works that the furnace in this trailer does not work above elevations above 4,500 feet. I recently took my trailer up to Mammoth Lakes in California where the elevation is 7,800 feet. That is when I discovered that during the 30 degree evenings that the furnace would not work. My wife called the extended warranty number that we had as we did purchase the 3 year extended warranty plan. When we never received a call back we contacted the dealer. The service department tried to help us over the phone but to no avail. It was only when I returned from my trip and I drove 1-1/2 hours to Santa Rosa RV Sales that I was told that my furnace would not work above 4,500 feet and that it is stated in the Suburban furnace manual. I contacted Forest River directly and was told the same thing. I think that the dealer and Forest River use deception in selling these units because this fact was never disclosed at any time and I only learned about it when I had the issue. Had I known this key piece of information I would have never purchased this unit. There would be no reason for me to read through all of the manuals thoroughly unless I was having an issue. Has anyone else experience this issue and were you able to get this issue resolved? My cousin was camping with us in a 2012 Forest River Motorhome and his Suburban furnace worked the entire time that we were at Mammoth Lakes. I appreciate any information or light that anyone can shine on this matter.

Is there a model number on your furnace and what brand is it? 

Seems odd to me that it won't work above that elevation. 

Perhaps it needs an adjustment or cleaning or some form of maintenance, but 4500 feet is a ridiculously low altitude as a limit. As Arch asked, a model number of your Suburban might help someone look further, and if you have a manual for the furnace you should check its limitations yourself, not depend on a dealer. Sales folk aren't always trustworthy.

What is the furnace model number?  I wouldn't get too upset about this one issue or  RV'ing may not be for you. There could well be other issues to work through. If you had been here before you shopped you may very well have been told things such as "If the dealers lips are moving he's lying". So now the best thing to do is educate yourself or just sell it.

At higher elevations the air is Thinner. it may simply need an air/fuel ratio adjustment. This is normally a sliding damper in the air flow. open it up a bit more to get a proper burn.

That said I've never heard of a furnace crapping out at high altitude either. Generators yes. but not Furnaces.

I have heard of them crapping out at 30 degrees though.. NOT a Furnace problem. Wrong fuel (Butane instead of Propane).

Thank you all for your responses. The model number of the furnace is a Suburban NT-20SQ. I have spoken with both the service technician at Santa Rosa RV Sales and with the service department at the home office of Forest River in Indiana. They both are sticking by the story that this furnace will not work above 4,500 ft elevation and that there are no adjustments that can be made. I find this very odd as most camping destinations are in the mountains where elevation becomes a huge factor. Again any other suggestions or light that anyone could suggest regarding this matter would be greatly appreciated.

Here is a copy of the manual, which does not contain the words elevation or altitude, nor even the number 4500. Your dealer is blowing smoke. Here is a copy of the installation manual. Here is a copy of the Service and Training manual.

They were easy to find with the google search term "Suburban NT-20SQ manual" (without the quotes, of course).

Thank you Larry N. I went to the trailer to get the manuals and you are correct. I cannot find anywhere in the manuals that I was provided or the ones that you copied me on that states that the Suburban furnace does not work above an altitude or elevation of 4,500 ft. I will be contacting them this week to discuss this issue further.

I would contact Suburban directly without giving any background and ask them if there are any altitude limitations. Then I would call the dealer and demand a fix.