Brown Water From the Faucet: Hot Side, Cold Side, and What Each One Means

Plumbing advice for South Carolina homeowners · Updated 2026-09-01

The first question is which tap

Before anything else, run the cold tap alone, then the hot tap alone, in a fixture you use every day. Which side the discolouration appears on narrows the cause immediately, and it is the first thing any plumber will ask you.

Brown on the hot side only

The water heater is the source. Every steel tank has a sacrificial anode rod inside it, which corrodes so that the tank does not. When the anode is used up, the tank lining starts to go instead, and rust washes into the hot water.

If the tank is under about eight years old, replacing the anode rod and flushing may buy you several more years. If it is over twelve, the discolouration is usually the tank telling you it is near the end, and it is worth planning a replacement rather than waiting for the floor to get wet.

Brown on the cold side only

The heater is fine; the pipe is the problem. Old galvanized steel supply pipe rusts from the inside, and rust flakes shed into the water, especially on the first draw of the morning after the water has been sitting still.

The same corrosion is narrowing the pipe, so brown water on the cold side often arrives alongside falling water pressure. Both are the same underlying issue and both are solved by repiping.

Brown on both sides

Look outside the house first. Municipal main flushing, hydrant use or a nearby main break stirs up sediment that has been sitting in the street main for years. This kind clears on its own within a few hours.

Run an outside hose bib for several minutes. If it clears, wait it out. If your neighbours have it too, it is definitely the supply and not your plumbing.

Yellow or orange rather than brown

Usually iron or manganese in a well supply. It is not harmful at typical levels, but it stains laundry and fixtures permanently and it is worth treating with filtration rather than a softener alone.

Is it safe to drink?

Rust in water is not toxic at these concentrations, but discoloured water should not be used for drinking, cooking or laundry until it clears, and you should not run it through a washing machine because it stains fabric. If it appears suddenly, does not clear, and your supplier has not issued a notice, get the cause identified rather than waiting.