Water hardness in Heilbronn
11.4 °dH very hard
Tap water in Heilbronn is very hard: 11.4 °dH (204 mg/L · 11.9 gpg · 20.4 °fH).
Source: Stadtwerke Heilbronn, Jahresmittelwerte 2025 (Kundeninformation, Zone 9 °dH) (2025) · data checked 2026-10-20
Range across supply zones: 161–321 mg/L.
4 supply zones — hardness varies by neighbourhood; the figure above is the median.
Hardness by district / supply zone
| °dH | mg/L | ||
|---|---|---|---|
| Zone 10 °dH (Härtebereich mittel) | 9.2 | 164 | hard |
| Zone 14 °dH (Härtebereich hart as printed) | 13.6 | 243 | very hard |
| Zone 14-18 °dH (Härtebereich hart) | 16 | 286 | very hard |
| Zone 9 °dH (Härtebereich mittel) | 9 | 161 | hard |
Stadtwerke Heilbronn publishes 2025 annual means as four zone sheets, and the city figure is a median of 203.5 mg/L CaCO₃ within a range of 160.7 to 321.3 mg/L. Which sheet applies depends on the street, so check the utility's street list before buying a softener. The utility's own class labels run from medium to hard.
German law (WRMG) uses 3 bands: soft < 8.4 °dH, medium 8.4–14 °dH, hard > 14 °dH.
Water data
| Total hardness | 11.4 °dH |
|---|---|
| Utility | Stadtwerke Heilbronn (Wasserversorgung) |
How Heilbronn compares
- Tap water in Heilbronn is close to the median of the 809 cities we track in Germany (11.5 °dH).
- By hardness it ranks 407 of 809 in Germany (1 = hardest); 49 % of these cities have softer water.
- In Baden-Württemberg it is number 81 of 146 cities; the regional median is 12.8 °dH.
- Nearest city with clearly softer water: Flein, 5 km away (9.1 °dH).
- Nearest city with clearly harder water: Ilsfeld, 6 km away (15.9 °dH).
Ranking of the hardest and softest water in Germany →
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 Heilbronn
| Brand | Setting for this water |
|---|---|
| Bosch | H03 |
| Miele | 11 °dH |
| AEG / Electrolux | 3 |
| Beko | 3rd |
| Hoover | S2 |
| LG | H2 |
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 Heilbronn water hard or soft?
It is very hard: 204 mg/L as CaCO₃ (11.9 gpg, 11.4 °dH). The usual bands are soft < 60, moderately hard 60–120, hard 120–180 and very hard > 180 mg/L.
Is tap water in Heilbronn safe to drink?
Hardness is not a health issue; it is about limescale, taste and appliances. Mains water must meet national drinking-water standards. German law (WRMG) uses 3 bands: soft < 8.4 °dH, medium 8.4–14 °dH, hard > 14 °dH.
How many grains per gallon is Heilbronn water?
11.9 gpg, equal to 11.4 °dH, 20.4 °fH or 204 mg/L calcium carbonate.
What dishwasher salt setting should I use in Heilbronn?
For 204 mg/L (11.4 °dH) check your manufacturer's table: maximum level (5–7).
Do I need a water softener in Heilbronn?
Yes, unless you are only passing through: scale damages appliances within a few years.
Source
Source: Stadtwerke Heilbronn, Jahresmittelwerte 2025 (Kundeninformation, Zone 9 °dH) (2025). Method: figure published by the water supplier. Stadtwerke Heilbronn, Jahresmittelwerte 2025 (Kundeninformation, Zone 9 °dH) · Outdated figure? Tell us