Hard water scale in the heater and drum
London's water runs at roughly 250–350 mg/l calcium carbonate, among the hardest in the country. Scale builds on the heating element, which is why machines here smell and struggle to heat properly years before an identical machine in a soft-water region.
Every visit includes a descaling service wash at temperature, run through the whole drum and heater circuit, not just a wipe of the visible parts.


