Water heater leaking

: I have a fairly new (5 years) water tank. I noticed it leaking from the brass tap on the side near top of water tank. Can you tell me how I can fix this? I have heard about anode being full. What is an anode? : thanksA anode is put into the tank to sacrifice itself against the harsh eliments in the water. Once the anode is depleated and if it is not replaced the harsh water will start to attack the tank, and eventually a leak will appear. You will have to investigate the leak a little further if it is the tank it will have to be replaced. If it is coming from a theaded fitting it most likly can be repaired by removing the fitting and replacing it with a new fitting of the same.