Yes — filtered, and depending on where you live.
Find out your hardness first
Your water utility publishes it by postcode. Two minutes, and it settles the question.
- Above ~150 ppm: hard. Filter, without exception, and descale on schedule.
- 50 to 150 ppm: the useful range. Filtering still helps with chlorine.
- Below ~50 ppm: soft. Scale is not your problem; flat-tasting coffee might be.
Why unfiltered hard water kills machines
Limescale deposits on the heating element and through the pipework. It insulates the element, restricts flow, and stops valves seating. The machine gets slowly worse for years and then stops.
Three to five years on hard water unprotected; often past ten with filtering and descaling.
Chlorine
Municipal water is chlorinated, and chlorine is perceptible in coffee well below the level you would notice in a glass of water. Any carbon filter removes it.
What not to use
Distilled or RO water alone — no minerals means poor extraction and hollow coffee, and some machines cannot even detect it.
Softened water — ion-exchange softeners swap calcium for sodium, which prevents scale and makes coffee taste flat and salty. Use an unsoftened tap.
The cheapest insurance in coffee
A filter jug is about thirty euros a year and roughly doubles machine life on hard water.
Last reviewed 8 August 2026