Fixing Rusty Hot Water and Discolored Water

Troubleshooting rusty hot water in the electric and gas water heaters. What is the cause of the discolored water with the rusty or brown in color appearance?


The cause of the rusty hot water appearance

With the first signs of the discolored hot water, such as rusty or brown in color appearance, many consumers will assume that their gas or electric heater got corroded. So, is the rusty fluid coming from the rusty tank or something else is going on?

There are several reasons for the rusty appearance:

  • Water softener resin.
  • Rust from the plumbing system.

Water heater tank corrosion

If you look at most of the tank-type heaters today, no matter electric or gas-powered ones, you will see that almost all of them are equipped with the metal tank. Inner surface of the metal tank is exposed to different water conditions such as corrosion.

In order to prevent corrosion and rust, manufacturers will cover the tank with the glass-porcelain coating treated with the high temperatures. This is what prevents the tank from rusting (anode rod is another element). If for any reason the glass lining is cracked hot water can get in touch with the metal and after some time corrode the tank. The water will then be in contact with the rusty spots on the tank, which will change its color.


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Bacteria as the result of the rusty hot water

This bacteria is actually an iron reducing bacteria, usually found in soil, wells and water distribution systems. Soluble iron is actually food for this bacteria, which will, with the lack of the oxygen and no water movement inside the tank, reduce the anode rod efficiency and speed up the corrosion.

Water mains

The rust is also found in the main pipeline that is delivering you water, since they are made of the cast iron pipe or metal.

Incoming water might bring clay, mud and sand deposits if your home plumbing is connected to the well system. If there is a break on the main plumbing system, or new houses are built, the dirt, mud and clay will enter the pipeline system and mix with water, resulting in brown or rusty appearance.

Now, as your heater is between the tap and the main plumbing, it will collect the dirt coming from the outside supply pipeline so the hot water will have this rusty or brown color look.

Universal solution for the rusty hot water

One of the solutions for the rusty hot water, excluded hard conditions such as rusty tank, is to drain and flush the tank thoroughly through the drain valve. If the heater tank and plumbing system is infected with the bacteria than shock therapy with the chlorine should be applied.

Most of the time heaters are blamed for the rusty hot water and other changes in color. Keep in mind that both electric and gas-powered heaters are built with the quality tank glass lining so it is very rare to see cracks in the lining that will allow water to contact the metal tank and result in corrosion.


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