Executive Summary: Sector SO25 1 vs Sector SW1A 1
Comparing tap water mineral concentration between Sector SO25 1 (Southern Water) and Sector SW1A 1 (Thames Water) reveals a water hardness difference of 5 PPM. Sector SW1A 1 has softer water at 275 PPM (Hard) compared to Sector SO25 1 at 280 PPM (Hard).
Limescale risk and boiler heating efficiency vary based on these mineral levels. Households in Sector SO25 1 experience higher heating element degradation and kettle scale accumulation due to elevated calcium carbonate density (280 PPM vs 275 PPM).
For home appliance setup, Bosch dishwasher water softener settings should be calibrated accordingly: Sector SO25 1 requires setting H04 whereas Sector SW1A 1 recommends setting H04.