A home's hot water heater should last for many years, but it will eventually need repair or outright replacement. The expected lifespan of the tank, as noted in its owner's manual, might tell you when you should expect to need to replace the hot water heater, but keep in mind that this expected lifespan is not a guarantee of the equipment's longevity! Hard water minerals can damage the inside of a hot water heater, or pipes can get rusted and this rust can settle inside the heater, or the tank may suffer early damage for a number of reasons. Note a few signs that it's time for you to reach out for hot water heater services.
When you turn on the hot water taps or showerhead and hear a distinct rumbling sound, this often means that hard water minerals have settled inside the heater. These minerals will typically harden and cling to the insides of the heater, but may also fall to the bottom of the tank. As the heater empties and then fills with water, these minerals will "slosh" around the tank and create that rumbling sound. They will also typically damage the inside of the tank, the pipes, the thermostat, and all other pieces of the heater! You may even notice that the hot water temperature is unreliable, and this often means the heater is damaged and needs replacing due to these minerals and crystals clinging to its insides.
Rust in your home's water can be caused by rusted pipes outside the home, or the water source itself may be contaminated. However, this can also mean that the inside of the hot water heater has developed rust, and those flakes are now getting into the water. Once the hot water heater rusts to this extent, it's usually beyond repair and needs replacing.
Higher utility bills
If your utility bills are suddenly getting higher, and especially if you notice that the home's hot water isn't always as hot as it should be, this can mean that the components of the hot water heater are breaking down. The heating coil may be drawing more electricity in order to maintain its warmth, or there may be leaks and cracks in the heater that are letting out that heat. An insulation blanket meant for heaters can keep that heat inside the tank, but in many cases, the tank is damaged beyond repair and needs outright replacing.