As it's been said, Dometic should have a switch to turn off the heater of the fridge/freezer wall.
Though, there is something wrong. What 2oldman said - make sure it runs in LP mode, duh :) ...
My Norcold - same size - has no switch, so the heater is always on, and yet it draws only ~12 AH in 24 hours on the medium setting. Propane fridge together with LP sensor (it's always on) shouldn't draw more than 16-19 AH. Your 225 AH bank should last 5 days before it drops to 50% IF there are no other loads.
