If this tank is made of steal or iron then you can make welding to fill the hole. If it is of plastic or fiber then you need the same material in the melt form to fix it.
I Have A Small Hole In My Hot Water Tank... Anyway To Just Patch That? It's Just A Drip.
Replace the tank, it's going to get worse
If you can see a pin hole, prepare yourself for a space filled with water when the hole enlarges. The tank is over six or seven years old or do you have a high acid water? This could cause an early rust thru from the tank's interior. Inspect the piping going into and out of the tank for any water leaks. Only solid galvanized water tanks say fifty or sixty years old have a metal wall thickness which permitted a prepared gasketed push-through bolt repair. If you have a functioning unit that old, hang onto it the Smithsonian Institute maybe be interested in acquiring it, for a display!
Start comparing prices for a replacement water heater or better yet look into installing an Instantaneous Unit. That type can require a lot of repiping and installation of electric power cable or gas lines or gas exhaust flue to the exterior etc.
Start comparing prices for a replacement water heater or better yet look into installing an Instantaneous Unit. That type can require a lot of repiping and installation of electric power cable or gas lines or gas exhaust flue to the exterior etc.