Welcome to the forum. I believe the 2018 has the 6 gal tank water heater with either 120vac heater element or propane. Since no one has responded so far I will do a re-direct to another entry on the forum which was a similar stated problem. Saves asking the same questions......I never got a response there though.....yet.
http://www.thorforums.com/forums/f8/...sue-18059.html