UK Water Quality Report • 2026 Data

Water Hardness in W1W

Water supply analysis across 4 postcode sectors in W1W (Thames Water).

Outcode Avg Hardness275 PPMHard Water
Regional Quality Overview

Water Supply Analysis: Outcode W1W

For residents and businesses in outcode W1W, understanding local water chemistry is essential for appliance longevity and limescale prevention. Our environmental data shows that W1W averages 275 PPM in mineral content, falling into the Hard Water classification.

Water chemistry can fluctuate across supply zones in W1W. The lowest mineral concentration is recorded in sector W1W 5 at 275 PPM, whereas sector W1W 8 experiences higher mineral levels reaching 275 PPM.

Due to the hard water (275 PPM) in W1W, limescale build-up can occur on heating elements, shower heads, and boilers. Setting your dishwasher water softener to the correct level (e.g. Bosch setting H04) is strongly recommended to prevent cloudy glassware and internal scale accumulation. Review the individual postcode sectors below to get precise dishwasher salt settings and limescale recommendations.

Softest Sector in W1W

Lowest mineral concentration

Softest
Sector W1W 597 Postcodes • Hard
275 PPM19.3 °Clark

Hardest Sector in W1W

Highest mineral concentration

Highest Hardness
Sector W1W 8142 Postcodes • Hard
275 PPM19.3 °Clark

All Postcode Sectors in W1W

Select a postcode sector below to view exact water softener salt settings, limescale protection guides, and appliance recommendations.