How do I descale a coffee machine?

Run a descaling solution through the water path, then rinse thoroughly. Frequency depends entirely on water hardness.

Descaling removes calcium carbonate deposits from the boiler and water lines. It is the single most important maintenance task.

How often

Driven by water hardness, not by time.

Very hard water — every 4 to 6 weeks. Medium — every 2 to 3 months. Soft or filtered — every 4 to 6 months.

Most bean-to-cup machines count brews and tell you. Believe them.

Empty the drip tray and remove any water filter — descaler destroys them.
Fill the tank with descaling solution at the stated dilution.
Run it through the brew path, in stages, with pauses to let it work.
Run it through the steam wand and hot water tap too. These are separate paths and people forget them.
Empty, rinse the tank thoroughly, and run two full tanks of clean water through everything.

Citric or lactic acid based descalers, or the manufacturer’s own. Cheap and effective.

Vinegar works chemically and is a poor choice: it damages seals over time and the smell persists for many cycles.

Scale insulates the heating element, so the machine brews cooler and takes longer to heat. Then it blocks lines and valves.

Descaling is not a repair. A machine already blocked by years of scale may not recover, and boilers can be destroyed outright.

Filter the water. Prevention costs less than any of this.

Last reviewed 8 August 2026