We had a Hansgrohe shower for 15 yrs and decided to replace it when the mixer bar thermostat failed. Pity because the exterior surface was pristine. We were so pleased with the brand that we went for a new top-of-the-range Hansgrohe model. After a year brown stains appeared on the mixer bar and vertical pipe leading to the shower head. German HQ says this is copper showing through the chromium and is attributable to the shower cleaner we use. They refuse to honour the guarantee. We have pointed out that both old and new showers were subject the same regime for showering and cleaning and that the new product is substandard compared to the old one. However they refuse to accept liability. I don't like giving negative reviews but I am incensed by their refusal to accept the evidence and offer recompense. So Buyer Beware - the guarantee is worthless.