The AQUA-HOT fluid can be run through the engine as we have a switch on the dash that allows us to do just that. We can heat the engine with the electric engine block heater OR we can heat the engine block with the AQUA-HOT system running the coolant through the engine to heat it.
It could be that not all AQUA-HOT systems have that option as ours has the two stage electric (110 and High), which involves two elements. On cool evenings, I can run the AQUA-HOT on just the electric alone.
So, you have to see which system that the coach has that you are considering.
MM.