Don't know the make/model of your TT's water heater but it may be possible depending on the plumbing layout. Our Jayco WhiteHawk has an Atwood water heater. The bottom of the tank is actually an inch or two below the drain plug. The trailer has two low point drains between the galley and bath. When opened one is draining hot water (as in steaming if the water heater had been recently running)the other is draining cold water. I never remove the drain plug now, simply open sink and kitchen faucets fully and the drain valves.
