Typically, the average water heater will last homeowners anywhere between 8 to 12 years.  Much of this depends on what kind of water heater you have. Traditional gas-powered heaters will usually start experiencing serious problems before ten years.  While electric tankless water heaters can last as long as 20 years. As with most household appliances, how much you use your water heater and how well you maintain it will shorten or extend its lifespan.   Do you know how old your heater is? If not, find the serial number located on your water heater. Serial numbers will be a letter followed by 9 digits. To figure out the age just consider the first three characters.  The first letter indicates what month it was manufactured in, for example, A would be January and M would be December. The next two digits will tell you the year, so C09 would indicate that the water heater was made in March 2009.
 

Rusty colored water is a clear sign that something is wrong.  The tricky part is determining whether the problem lies in your water heater or the pipes. Regardless, the problem needs to be solved in order to maintain a healthy home. If the tap water is coming out rusty, you can run a quick test to determine where the rust is coming from. Start by draining hot water directly from your water heater’s drain valve into a clean bucket.  Repeat this process several times, if by the third full bucket you find that the water is still rusty, then your water heater is the problem, not the pipes.  If it is clean, then it is probably your home’s internal piping. Usually, rusty water can be attributed to an old water heater. At some point, water heaters will accumulate rust and must be replaced.

Tap water is not as crystal clear as the water found in plastic bottles. Although it is perfectly safe to drink and bathe in, there are microscopic traces of sediment found in tap water.  After many years, this sediment will build up on the bottom of a water heater tank.  The process of heating and reheating every day will cause this sediment to harden. Hard sediment will move around when heated up and bang against the steel encasing. If you hear rumbling noises, there is probably sediment in your tank, which is a clear sign your water heater is reaching the end of its life. This sediment decreases efficiency which will increase bills and will continue to cause more damage to your tank. Eventually, the constant banging could cause the steel to deteriorate, brittle, and leak. Sediment is usually from calcium carbonate found in ‘hard water’, which will leave a chalky residue deposit.

Another clear sign of a water heater problem is discovering water around the tank. Before you freak out and think you need a new heater, make sure to check the fittings/connections to the tank and the temperature overflow pipe. First, make sure all the connections to your tank are tight. Then run your water heater and see if there is any water coming out of these external pipes. If so, then you will need to replace these connections.  If no water is trickling out of the fittings or the overflow pipe, then the problem is most likely your water tank.  Hot water causes the metal tank to expand and contract when it cools. After thousands of heating cycles, many tanks may develop a small fracture. At first, this fracture may not be easy to spot, and may only leak when the water heater is heating up (subsequently causing expansion).  Wait till the height of each heating cycle to check if any water is leaking from a fracture.