Hi guys it's been a while since I have posted. My '99 HR Vacationer is parked in MD all winter in my driveway. As I will be using it about twice per month this winter I am not planning on winterizing it. My question is how do I tell if my tanks are heated, I have no indication they are from the owners manual and original window sticker. Looking underneath the rig they are heavily boxed in with insulation (some type of foam looking material that hardens once sprayed like Great Stuff) then it was sprayed over with undercoating. My plan was a electric liquid filled radiator in the living quaters and a small ceramic heater in the sewer bay set on about 45 degrees to keep things from freezing up My problem is the tanks. Any advice is appreciated. Thanks.