There's a promo sub-thread (?) on the site from an RVer recommending a Camco57341 Wave-[number] (they have Wave-8) Safety Heater, propane fueled, safe for interior use. Anybody have experience with one of these?
Their contribution shows very clear photos of the T they made off the propene line just before the OEM heater, the line running through cabinets, and the heater in use in the middle of the floor. The poster said they use it dry camping when they can't plug an electric space heater into shore power. It's presented as a more economical and silent alternative to the OEM furnace and without a drain on batteries.
Just found the link:
https://letsrv.com/mod-for-cold-weather-rv-living/