Thor Tuscany Motorhome's Aqua-hot,do you want that in an RV?

You are equating diesel operation with an engine. The Aqua-Hot is much much quieter. Some people think there is an objectionable odor when they run. If they are set right I don't think they have an objectionable odor. They really get a coach warm in the morning.

You typically use just AC for just hot water. The diesel is typically only needed when you need coach heat or you are dry camping and do not want to run the generator to heat the water.