Rust is one of the worst enemies of the water tank; not only does it weaken the tank walls, but it also leads to accumulation of sediment at the tank's bottom. The sediments reduce the efficiency of the water heater and waste energy. Although you cannot eliminate rusting in water heaters, you can reduce the rate of rusting if you understand what causes it. Causes of rust include:

Intrinsic Rusting

Water heater tanks are made of metal, and metal corrodes when it comes into contact with water. This is something that cannot be prevented, but the tank manufacturers slow it down by installing sacrificial anodes. The sacrificial anode is a metallic bar that corrodes in lieu of the tank because it is made of metals that are more reactive than the tank metal.

To prevent internal rust, you should have the sacrificial anode rod replaced when it gets too thin. According to, you should replace the anode when it is eroded to half its original size, which usually takes a year.

Alternatively, you can install a second anode for additional protection. Another option is to install a powered anode, which does not need replacement but costs several times the conventional anode.

Corrosive Fumes

Water heaters draw in the surrounding air for combustion, and the quality of this air affects your water heater. For example, if the air is acidic, then the tank will corrode faster because acid accelerates the rate of combustion. Numerous household products such as drain cleaners, car batteries, and some washing detergents are acidic. Therefore, if you store them near your water heater, then they may contaminate the combustion air and corrode your tank. The effect can be especially pronounced if the tanks and the acidic products are in a confined space.

Transient Current

Your tank can also corrode due to electrochemical processes, which happen when unintended electric current flows through your tank. This current, which is known as transient current, can come from different sources such as lightning, poorly insulated wires in the tank, and other nearby conductors.

The solution to this problem is to have your tank grounded. Your plumber, such as from Ace Plumbing, Heating and Air, should connect the outgoing and incoming pipes with copper metal, and then ground the copper wire at the main electrical panel. That way, a transient current that jumps to the tank is channeled to the ground.

Dealing with corrosion will help you to prolong the useful life of your water heater. You should not wait until rusty or dirty water starts coming out of the tank. Inspect your water heater regularly to preemptively address rust issues.