I used one in an older RV that had a gas only heater - worked fine. If its an Atwood heater, it has no anode rod anyway, so there is no downside. If a Suburban that needs an anode rod, then there is a drawback to losing the anode function.
Former owner of 2004 American Tradition and several other RVs
Home is in the Ocala Nat'l Forest near Ocala, FL