Why is my hot water brown?
Brown or rusty hot water usually indicates corrosion inside the tank or a failing sacrificial anode. Sediment build-up at the bottom of the cylinder can also discolour the water and reduce efficiency.
If only the hot water is discoloured, have the system inspected promptly — replacing the anode early can extend the tank's life, but ongoing rust often signals the tank is near the end of its life.
What brown hot water usually means
If only the hot water is discoloured, the cause is almost always inside the hot water system — typically corrosion in the tank or a sacrificial anode that has worn out and stopped protecting the steel. Sediment build-up at the bottom of the cylinder can also stir up and discolour the water, often just after the system reheats.
If both hot and cold water are discoloured, the issue is more likely in the mains supply or your pipework than the hot water unit — for example after water-main work in your street.
Is it safe?
Discoloured water is usually a system-condition issue rather than an immediate hazard, but rusty water can stain laundry and fittings and signals the system needs attention. If the water also smells strongly, looks very dark, or suddenly appears across the whole home, stop using it for drinking and have it checked.
When to seek help
Have the system inspected promptly if the hot water stays discoloured. Replacing the anode early can add years to a tank's life, but if the tank has corroded internally, ongoing rust usually means it's near the end of its service life and replacement is the more economical path.
A note on limitations: the only way to confirm whether it's a simple anode or flush versus end-of-life corrosion is to inspect the system — age, tank condition and water quality all play a part. We assess it and explain your options before any work.
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