I have the 2012 Georgetown 378XL and the low point drains are under the fresh water tank compartment, that's the compartment next to the water heater. Also on the H/W bypass look under the water heater and you will see a access cover unscrew the cover and look in the hole and you will see your valves, there are (3) valves the bottom and top need to be turned 90 degrees and the one in the middle needs to be turned 90. this will close the water supply to tank and open the bypass. Just remember to swap them when de-winterizing.