The water heater is easy. Just turn it off when sleeping and the burner will not be heard. If heating water via electricity, in time the element will make noise as it begins to corrode. Again, the solution is to turn it off at bedtime.
Boondocking in remote areas essentialy means no electric without a generator. If willing to suffer a remote generator or have electric, there are electric options for a furnace. In the small confines of a TC, a 1500w portable electric oil radiator heaters and fans can be quiet and very effective. Otherwise, anything with a burner or a fan will be heard at startup. I even wake up when I hear the little burner on the fridge start. I feel her pain.
Learning to sleep with low level music on all night has helped the burner, fan, and other appliance noises to be less noticeable.
