Rusty or smelly hot water: the anode rod nobody told you about

Brown tinge in the first draw, or a faint sulphur smell that is only in the hot tap. Both point at the same forgotten part.

What the anode rod is

A magnesium or aluminium rod hanging inside the tank. It is more reactive than the steel tank, so corrosion attacks it first. It is designed to be consumed. Once it is gone, the tank lining is next.

The signs it is spent

• Rust-coloured water from the hot tap, clearing after a few seconds
• A rotten-egg smell in hot water only
• Metallic taste
• Flakes of scale or rust in the bucket
• The geyser is three or more years old and has never had the rod checked

Why hard water speeds it up

High mineral content makes the water more conductive, so the anode gives itself up faster. In the tricity, a rod that would last five years elsewhere can be gone in two.

The fix

Drain the tank, unscrew the old rod, fit a new one, refill. An hour, and the rod itself is a modest part. Left too long, the alternative is a tank that starts weeping at a seam — and that is a new geyser.

The smell is not harmful, but it is a countdown. If the water smells and the geyser is over three years old, book the rod check before winter — a failed tank in December is the worst timing there is.