Although your water heater doesn't start flashing red lights when it needs to be replaced, it may exhibit warning signs that can help you decide whether you need a new water heater. The key is knowing whether a relatively minor repair will keep you in hot showers for a couple more years, or whether it will be the first of multiple repairs.

Does Your Water Heater Take Longer Than in the Past To Provide Hot Water?

The most common warning sign that your water heater is nearing the end of its useful life is that it takes longer to heat the water--or fails to heat it at all. If it is getting colder outside, however, the problem may be solved by raising the temperature setting on the water tank. Cooler outdoor temperatures may require the heater to work harder just to maintain the same temperature. If this adjustment fails to work, you may need a new water heater.

Does Your Water Heater Have a Leak?

Perhaps the most significant warning sign you can use to determine whether you need a new water heater is a leak. If there is just a small drip, the leak may be repairable. However, if there is a leak in a seam--caused by damage, rust or weatherization--it may be difficult to repair. If you patch the water heater, the patch may come off. If you decide to weld the leak, that effort could further damage your heater and add significantly to your repair costs. You may well decide it's time for a new water heater.

Do You Get Only One Hot Shower?

A change in water heater capacity is another common warning sign. If suddenly there is less hot water, only enough for one hot shower, water heater failure may be imminent.

Does Turning on a Hot Water Spigot Yield Rusty, Brown Water?

This could be the result of bacteria or a failed anode rod. If either condition exists, it's time for a new hot water heater.

Is Your Water Heater Noisy?

Your water heater should not be noisy. A noisy water heater may be an early warning sign of a breakdown requiring an expensive repair.

Is There Calcium Buildup in the Water Tank?

During the life of a water tank, calcium and magnesium salts are deposited. Salt deposits rob you of hot water, making it more expensive to heat your water. If too much sediment adheres to the bottom of the tank, you may need to replace the water heater.

How Old Is Your Water Heater?

The life span of water heaters is 10 to 15 years. This is an important consideration in deciding whether you need a new water heater. If your appliance is in or very near this range, age may be starting to take its toll. When any of the conditions previously described exist, and a repair is needed, it is probably time to purchase a new, more efficient hot water heater.

Source:

How Do I Know When To Replace My Water Heater?