UK Water Quality Report • 2026 Data

Water Hardness in HP17

Water supply analysis across 3 postcode sectors in HP17 (Thames Water).

Outcode Avg Hardness275 PPMHard Water
Regional Quality Overview

Water Supply Analysis: Outcode HP17

For residents and businesses in outcode HP17, understanding local water chemistry is essential for appliance longevity and limescale prevention. Our environmental data shows that HP17 averages 275 PPM in mineral content, falling into the Hard Water classification.

Water chemistry can fluctuate across supply zones in HP17. The lowest mineral concentration is recorded in sector HP17 0 at 275 PPM, whereas sector HP17 9 experiences higher mineral levels reaching 275 PPM.

Due to the hard water (275 PPM) in HP17, 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 HP17

Lowest mineral concentration

Softest
Sector HP17 042 Postcodes • Hard
275 PPM19.3 °Clark

Hardest Sector in HP17

Highest mineral concentration

Highest Hardness
Sector HP17 915 Postcodes • Hard
275 PPM19.3 °Clark

All Postcode Sectors in HP17

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