WE also contemplated going to a tankless hot water heater. We almost always stay in a campground with at least water and electric connections - trying to get one with full hookups. The more hot water you use, the faster your holding tank fills. The more propane you use if not relying on electric hookup from CG. Think tankless runs on Propane? Since yours is an older rig (like ours) I wouldn't spend more $ than necessary for its upkeep. If you find you really enjoy RVing, you will likely want to get something newer in the future. BTW, we decided not to change from our traditional tank. Instead, we got a new shower head, an aerator one, and it works GREAT! Better water pressure, uses less water so the shower lasts longer! Might think about that. Cost was less than $50!