Short & direct
Tap water in the Zürich area is medium-hard to hard depending on the commune – roughly 14 to 25 French hardness degrees (°fH). Hard water causes limescale in boilers, fittings and household appliances. A water softener pays off mainly from around 25 °fH or with recurring limescale problems; your water utility can tell you the exact hardness for your address.
Furred-up fittings, white marks on glasses and a boiler that draws ever more energy: these are the classic signs of hard water. Here is how high the water hardness in the Zürich area really is and when a water softener is worth it.
How hard is the water in the Zürich area?
In Switzerland water hardness is given in French hardness degrees (°fH) and split into six levels:
- soft: below 15 °fH
- medium-hard: 15 – 25 °fH
- fairly hard: 25 – 31 °fH
- hard: 32 – 42 °fH
- very hard: above 42 °fH
In the Zürich area the water is usually medium-hard to hard. In the City of Zürich it is often around 14 – 19 °fH, because a lot of treated lake water is used. Communes in the Limmattal with a high share of groundwater and spring water can be noticeably harder. Your water utility can give you the exact value for your commune.
What hard water does
Limescale is harmless to health, but a nuisance technically:
- Boilers & heat exchangers scale up – raising energy use and shortening their lifespan.
- Fittings, shower heads and appliances (washing machine, dishwasher, coffee machine) suffer.
- More cleaning effort and higher use of detergents and rinse aid.
To get a scaled-up boiler back in shape, read our article on descaling a boiler.
When does a water softener pay off?
A water softener reduces hardness centrally for the whole house. It is particularly worthwhile:
- from about 25 °fH (fairly hard),
- with recurring limescale damage to appliances,
- for new, high-quality plumbing and heating systems you want to protect.
As rough guidance, a unit for a single-family home costs around CHF 2,000 to 4,000 depending on the model and connection. Salt and regular maintenance come on top.
Tip: A softening system must be installed and serviced professionally – only then does the water stay hygienically sound. Have the hardness measured before buying, rather than investing on a hunch.
Clean water, protected appliances
Whether it’s a hardness measurement, descaling or installing a water softener – we advise you honestly and only install what genuinely pays off for you. Learn more about our plumbing services here.
Call us on +41 44 747 06 61 or request your free quote.
Need help from a professional?
Free quote or 24/7 emergency – we are here for you in the Limmattal.