I was on vacation for a week, and when I returned I noticed that I did not have any hot water. When I checked the tank, I noticed that the pilot was unlit. Whenever I lit the pilot , there was water dripping on the pilot (from the inside of the tank, unsure of location). Once I turned the pilot off the water stops dripping. I thought that it was odd that the only time the water dripped was when the pilot was lit. When I spoke to my plummer he told me that I need to replace the whole tank, because it is rusting. There isn't any water around the tank at all, I do not want to replace the tank if it is not necessary. I would appreciate any help in this situation. Thanks

Your plumber told the truth. The tank is corrupt. It has a leak but only leaks when the heat opens the hole. The new tanks are succeptable to failure because of dust. Keep the area around your new tank vacuumed.