I have an Olympian Model 6100A heater I would like to sell. The heater is 8 to 10 years old, as a guess. Apparently I'm getting old, I just don't remember when I bought it, new. I checked with the company but they weren't a lot of help, since they purchased the company about 6 years ago. The gentleman I talked with told me from the serial #, he'd say 8 to 10 years. He also told me that the only difference between this model and the "Wave" model is cosmetics. The heater has been used very little and works just fine, I just don't have room for it and it's to big for the way I camp now. If I still had a trailer I'd probably keep it but my living space for camping is severely limited now since I camp from the back of my truck. Anyway, I paid over $300.00 for it when I purchased it. I'll sell it for $50.00 and you pay shipping from Grand Rapids, Mich.. When you receive the heater if you aren't satisfied just return it and pay nothing except the shipping.