Cheechako, I don't see any reason why not - if I'm not mistaken, the
Perkins 4-108 in a previous
boat of mine had the hot water run off from the
water pump to the water heater. Having said that, its been a long time since I installed a new water heater, but as I
recall you may need to install a vented 'loop' between the
diesel and the heater in order to avoid air locks.
Brad