Coleman stove 20 lb propane tank. Some heaters are labeled "high efficiency". First time out after winterized. Not rated yet Have a new RV and the 12 volt lights seem to be getting weaker by the day. I have replaced 2 Power Gear motors within a month. Why would it feel hot? Is there some way to lock it up while we are not there? This heater is somewhat more expensive than the Holmes, but has several additional features which I like: Thanks P. BUT, we can smell the toilet. I am looking for recommendation for tow vehicle for 31 foot Travel Supreme trailer.