Do you have a suspicion that something is wrong with your home's hot water heater? If so, it will help to know some of the signs that it is in need of repair.
Are you familiar with the sound a tea kettle makes when it is boiling? You definitely do not want to hear this sound coming from your hot water heater. This is often due to there being a lot of sediment trapped in the tank, and you have hot water that is seeping through that sediment. You will need to have your hot water tank drained of sediment in order to fix the problem since all that sediment is not good for the heating element.
Another sound you want to pay attention to is rumbling. This is a problem if you have cold water and hot water mixing together in the tank, which actually creates a rumbling sound to come from within it. You'll need to have a plumber investigate why it is happening since there could be a problem that is allowing too much cold water to enter the tank. This can also be due to sediment collecting in the tank.
There are good and bad leaks to have from a hot water heater. If the leak is coming from the shell of the tank, then that is a really bad leak that cannot be repaired. You'll likely need to get a whole new tank because you can't reliably patch a hot water tank to fix it. However, leaks from the pressure release valves and other connection points can easily be fixed if that is where the water is coming from.
If you do see rust on the outside of the tank and there is not a leak in the shell, then it may be possible to prevent the problem from getting worse. A replacement sacrificial anode rod may be necessary since this part is designed to corrode first before the shell.
Is the water coming from the hot water tank not getting as hot as it once was? This could be caused by two potential problems. You'll want to have the hot water tank's thermostat investigated because this helps control the temperature of the water. If it's reporting the wrong temperature then the heating element won't work properly. The other problem could be with the heating element itself, which will need to be repaired or replaced.
Contact a professional to learn more about water heater repair.