I have been using the little 3800btu heater in my fish house this winter and it works fine. I also have been using the refill adaptor on the bottles. I do notice the refilled bottles only last me around 3 hours where a brand new one around 5. But the directions say to have the little tanks cold and the big tank room temperature and I have not been doing that, both tanks are ice cold outside
A nice safety feature on it is if it gets tipped over or even bumped hard it goes out.