Why is my hot water brown?
Brown, orange or rusty water from the hot tap is a sign something is corroding, and the question is what. If only the hot water is discoloured, the hot water system is the usual suspect. If the cold is brown too, the cause is more likely in the pipes or the water main. Here's how to tell the difference, what each cause means, and when it's time to act.
Hot only, or hot and cold?
Only the hot water is brown
Points to the hot water system: a worn-out anode, rust inside the tank, or sediment that's built up in the bottom of the cylinder.
Hot and cold are both brown
Points to the pipes or the street. Old galvanised pipes rust from the inside, and work on the water main nearby can stir up sediment for a few hours.
The usual causes
- A spent anode: storage tanks have a sacrificial anode rod that corrodes so the tank doesn't. Once it's used up, the tank itself starts to rust. Replacing the anode in time can add years to the tank's life.
- A rusting tank: if the tank lining has failed, the water will keep coming out brown, and a leak usually isn't far behind. At that point replacement is the answer.
- Sediment: grit settles in the bottom of the tank over the years and gets stirred up by heavy use. A flush can help.
- Galvanised pipes: rust from old steel pipes discolours both hot and cold water, often worst first thing in the morning. See our galvanised pipes guide.
- Mains work: if the neighbours have brown water too, Sydney Water work on the main may have stirred up sediment. Run the cold tap until it clears.
What to do
Run the cold tap first. If it clears and the hot stays brown, the hot water system needs checking. Look at the base of the tank for rust stains or water, and note how old the system is (the date is usually on the label). We'll check the anode, the tank and the pipes, and give you options and a fixed price before any work starts, whether that's a new anode, a flush or a replacement.
Brown hot water in southern Eastern Suburbs homes
Many older homes in Matraville, Malabar, Botany and Maroubra still have galvanised pipework somewhere in the house, and plenty of hot water systems here are well past ten years old. Homes near the coast also see faster corrosion on outdoor tanks and fittings. If your hot water has started to discolour, it's often the early warning before a tank leak.
Why locals call us
- Local to Matraville and the southern Eastern Suburbs
- Free on-site quotes, with a fixed price before any work starts
- Lifetime labour warranty on our workmanship
- 100+ five-star Google reviews
- Licensed plumbers and gasfitters (Lic. 398171C)
Common questions
Is brown hot water dangerous?
Rust mainly affects taste, colour and staining rather than being an immediate danger, but it's a sign of corrosion that should be checked. Avoid drinking discoloured water.
Why is only my hot water brown?
Usually because the hot water system's anode is worn out and the tank has started to rust, or sediment has built up in the tank.
Can a hot water system be fixed if the water is brown?
Sometimes. If it's caught early, a new anode and a flush may be enough. If the tank itself is rusting, it needs replacing.
How often should the anode be checked?
Many makers recommend checking it about every five years, and more often where the water is harsh on tanks.
Related help: hot water repairs and replacement, hot water servicing, hot water guide, galvanised pipes guide and hot water running out. Local pages: hot water Matraville, hot water Malabar, hot water Botany and hot water Maroubra.