I have a 2015 Signature Ultra-Light Model 8315BSS that I purchased new in March of that year. First trip (in southern Michigan) in April and I thought I was gonna freeze the first night! Unfortunately, my unit doesn't have the fireplace option. I checked the furnace flow (bedroom is in the rear of the trailer) and discovered that the flow was virtually non-existent. Bought myself a nice little electric heater to get me by until I could return to the selling dealer (CW in north-central MI). They removed the underbelly covering and told me that there was a piece of the hose that had been smashed almost flat! They indicated they had opened it up by hand as best as they could. There was a slight improvement in the flow, but it's NEVER going to be adequate. So, the nice little heater that I initially intended for one or two camping trips now is a staple item to take along on my early spring trips so as to keep from coming down with frostbite. Just to clear the air, my little heater has a safety tip-over switch and is temperature and/or time adjustable. Hell, it even has a nice little remote so if I get too toasty in the middle of the night, I can turn it off without getting out of my warm bed. It's a Hampton Bay tower unit and I bought it at Home Depot for under $80 but I don't think they have this item any more. Alright, I've rambled enough. Just wanted to add my two cents.