OK this has gotten very confusing with replies, for which we are grateful, getting of the topic. It is not about money it is about not having to unhook the RV and drive it out to get propane then drive it back..back in our permanent site and rehook ..we LIVE in our RV, we are not traveling. We use microwave or ELECTRIC water kettle. We also use hot plates and toaster ovens. In 4 years we have never used the RV oven once and now never use the RV stove top. Just curious for the shower whether to keep the propaae heating ( it is now in the 40s at night) or just 15 minutes before a shower.