Water hardness in Winterthur
27 °fH very hard
Tap water in Winterthur is very hard: 27 °fH (270 mg/L · 15.8 gpg · 15.1 °dH).
Source: Stadtwerk Winterthur, Trinkwasserkennzeichnung 2025 (2025) · data checked 2026-10-20
Stadtwerk Winterthur prints a total hardness of 270 mg/L CaCO₃ (27 °fH) in its 2025 drinking-water label and names Töss groundwater as the source. That is well above the Zurich figure, and limescale on kettles and taps builds up quickly. We found one citywide figure and no zone breakdown.
In der Schweiz wird meist in °fH angegeben (1 °fH = 0,56 °dH).
Water data
| Total hardness | 27 °fH |
|---|---|
| Utility | Stadtwerk Winterthur |
How Winterthur compares
- Tap water in Winterthur is close to the median of the 650 cities we track in Switzerland (26.7 °fH).
- By hardness it ranks 313 of 650 in Switzerland (1 = hardest); 51 % of these cities have softer water.
- In ZH it is number 67 of 116 cities; the regional median is 28.4 °fH.
- Nearest city with clearly softer water: Kleinandelfingen, 12 km away (17.9 °fH).
- Nearest city with clearly harder water: Brütten, 5 km away (33.8 °fH).
Ranking of the hardest and softest water in Switzerland →
What it means at home
- Severe scale: heater elements and washing-machine heaters fail early.
- Detergent use is very high; taps and screens coat within days.
- Dishwasher at maximum salt setting.
- An ion-exchange softener is practically essential; RO for drinking water.
How much salt will you use for softening?
Yes. At this hardness a softener pays for itself through appliance life and detergent.
Descale a coffee machine or kettle about every 1 months (typical manufacturer guidance for this hardness).
Estimates for planning, not a quote. Check your appliance manual for exact settings.
Dishwasher setting in Winterthur
| Brand | Setting for this water |
|---|---|
| Bosch | H04 |
| Miele | 15 °dH |
| AEG / Electrolux | 4 |
| Beko | 4th |
| Hoover | S2 |
| LG | H3 |
From each brand's manual for the model family named in the source; your model may differ, so check its manual. All brands and how to change the setting →
FAQ
Is Winterthur water hard or soft?
It is very hard: 270 mg/L as CaCO₃ (15.8 gpg, 15.1 °dH). The usual bands are soft < 60, moderately hard 60–120, hard 120–180 and very hard > 180 mg/L.
Is tap water in Winterthur safe to drink?
Hardness is not a health issue; it is about limescale, taste and appliances. Mains water must meet national drinking-water standards. In der Schweiz wird meist in °fH angegeben (1 °fH = 0,56 °dH).
How many grains per gallon is Winterthur water?
15.8 gpg, equal to 15.1 °dH, 27 °fH or 270 mg/L calcium carbonate.
What dishwasher salt setting should I use in Winterthur?
For 270 mg/L (15.1 °dH) check your manufacturer's table: maximum level (5–7).
Do I need a water softener in Winterthur?
Yes, unless you are only passing through: scale damages appliances within a few years.
Source
Source: Stadtwerk Winterthur, Trinkwasserkennzeichnung 2025 (2025). Method: figure published by the water supplier. Stadtwerk Winterthur, Trinkwasserkennzeichnung 2025 · Outdated figure? Tell us