I own a brand new Thor ACE 30.3 with exterior kitchen. I am trying to sanitize the fresh water system before I use it for the first time. The tank was empty before I started. I put the water/bleach solution in, filled the tank with water, drove around for about five minutes to mix the solution with the water. Then I turned on the water pump and ran all the faucets one at a time to get air out of the lines and have the lines filled with the water/bleach solution. After I ran the water though each faucet, everything seemed fine except the sink in the outside kitchen did not drain. I tried everything I could think of. Does anyone have any idea why it won't drain and what I can do. It is the first time it has ever been used.