Park the motor home and set the emergency brake. Open the fresh water tank drain and let all the water leave the tank. Go inside and turn on all the faucets and let any residual water drain from the taps. Turn the faucets off.
Mix one cup of bleach to three gallons of water in a bucket. Open the fresh water tank intake hose and place a funnel in. Pour the bleach water solution into the fresh water tank, allowing the water to run over the hose via the funnel. Let the bleach solution sit in the tank for 30 minutes. Add half a tank of water to the tank and drive the motor home so the water sloshes in the tank, cleaning the inner walls.
Park the motor home and fill the fresh water tank all the way to the top with water. Go in the motor home and turn on all the faucets and let the water run until you notice a faint odor of bleach in the cabin. Turn off the taps.
Drain the fresh water tank of the bleach solution and water. Fill the tank once more with fresh water and turn on all the taps. Let the tank empty via the taps. This removes the bleach from the system.
Fill the motor home fresh water tank with fresh water. The system and tank is now sanitized and ready for a full season of use.
