UK Water Quality Report • 2026 Data

Water Hardness in KT4

Water supply analysis across 3 postcode sectors in KT4 (Thames Water).

Outcode Avg Hardness270 PPMHard Water
Regional Quality Overview

Water Supply Analysis: Outcode KT4

For residents and businesses in outcode KT4, understanding local water chemistry is essential for appliance longevity and limescale prevention. Our environmental data shows that KT4 averages 270 PPM in mineral content, falling into the Hard Water classification.

Water chemistry can fluctuate across supply zones in KT4. The lowest mineral concentration is recorded in sector KT4 8 at 260 PPM, whereas sector KT4 9 experiences higher mineral levels reaching 275 PPM.

Due to the hard water (270 PPM) in KT4, 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 KT4

Lowest mineral concentration

Softest
Sector KT4 8286 Postcodes • Hard
260 PPM18.2 °Clark

Hardest Sector in KT4

Highest mineral concentration

Highest Hardness
Sector KT4 915 Postcodes • Hard
275 PPM19.3 °Clark

All Postcode Sectors in KT4

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