Have you just moved into an older home with a water heater that is also best described as "old?" If so, you are probably wondering if it is okay to use that hot water heater. The answer, as frustrating as it might be, is "it depends." Although the life expectancy of a hot water heater is about 10 years, many keep functioning far longer than this. To determine if your water heater is okay to use, or whether it needs some service before you use it, do your own inspection and look for the following issues.
Leaks Around the Tank
If the tank is not already full of water, turn on the water supply valve and let it fill up. Then, keep checking around the tank every couple of hours to see if there are any drops of moisture on the floor. If you do see a leak, then you will want to call a water heater repair service before using the tank. Unless you see visible rust on the bottom of the tank and water coming through a hole, the water is probably just coming from one of the valves. Valves are easy to replace, but you do need to replace a leaky valve before using the tank, or else you might come home to quite the flood.
If you are able to fill the tank and leave it without any leaks, then you can turn it on and have a listen. As the water starts heating up, do you notice any rattling or rumbling noises? These usually indicate that there is a lot of sediment in the bottom of the tank. It's okay to use the tank with this going on, but you do want to have it addressed soon since sediment reduces efficiency can can cause the tank to wear out faster. Your water heater repair person can come drain some of the water out; the sediment should come with it.
Water That's Not Not
After the tank has a chance to heat, go upstairs and turn the water on. Is it reasonably hot? If not, double check that the temperature setting on the tank is adequate. You usually want it set to between 120 and 130 degrees F. If the setting is correct but the water is not getting warm enough, you could have any number of issues. In an electric water heater, the burner could be burned out. In a gas tank, one of the gas injectors could be clogged. A repair person can figure it out and then let you know whether repairs are a possibility.
Sometimes older water tanks surprise you and keep chugging along for years. If your tank is not leaking, doesn't rattle, and still warms up the water, then feel free to keep using it.