I have a 2022 IDM223RK and the water heater does not function on shore power. After a bit of research and discussion I removed the partition and found that there is a 110V chord just hanging out down there. The water heater is the Dometic WH-6GEA and after some additional googling I realized that this is in fact the power chord and it should be plugged in. For fun I plugged it into an extension chord and an interior outlet and the the water was hot enough to burn... All of that being said where should the outlet for the water heater have been installed, I cannot see any provision for it and the chord is relatively short. The individual I spoke to at Heartland was unable to find any photos or wiring diagrams to help.