Yes, every part of London has hard water. Independent figures put all 32 London boroughs between 219 and 327 ppm, and the average is 276 ppm, which counts as very hard. That is why kettles fur up, shower screens cloud over and combi boilers lose efficiency across the capital.
Check the hardness for your postcode to see your exact figure.
Why is London water so hard?
Most of London's water comes from the Thames and Lee and from underground aquifers. Before it reaches your tap, it passes through chalk and limestone across the South East and picks up dissolved calcium and magnesium. Thames Water says this is why all the water in its region is hard. Affinity Water (north-west London) and Essex & Suffolk Water (east London) supply similar hard water.
London water hardness by borough
Ranked from hardest to softest, in parts per million (ppm) of calcium carbonate. Above 200 ppm is hard; above 300 ppm is very hard.
Borough figures: Aspect, rounded. Hardness varies by street and supply zone, so check your own postcode for the most accurate figure.
Signs of hard water in a London home
- White scale inside the kettle and on taps
- Cloudy shower screens and blocked shower heads
- Spotty glasses from the dishwasher
- A noisy or less efficient boiler
- Needing more soap, shampoo and detergent to get a lather
- Skin that feels tight or dry and hair that feels dull after washing
What can you do about London's hard water?
Pick the option that matches the problem and your budget. Only a water softener actually removes hardness; the others reduce or manage scale.
Water softenerRemoves the calcium and magnesium that cause limescale, for the whole home. Best for homeowners who want limescale gone everywhere.
Non-electric softenerSoftens using water pressure, so no power socket is needed. Best for flats and tight spaces.
Scale reducerReduces scale sticking to heating elements but does not soften. Best for protecting a combi boiler on a budget.
Polyphosphate dosingKeeps minerals in solution so they scale less. Best for boilers and water heaters.
Drinking water filterImproves taste and reduces chlorine at one tap. Best for better-tasting tea and drinking water.
Not sure which suits you? Read our guide to choosing the right water softener, or see how hard water and limescale affect your home.
Living in a London flat?
A softener can still fit. Compact cabinet models sit in a kitchen cupboard, and non-electric models need no socket. See our guide to water softeners for London flats.
Why buy from Wrekin Water?
- 15 years trading, with a team of over 25 years' experience
- More than 50,000 customers and an Excellent Trustpilot rating
- UK-wide delivery to every London postcode
- Plain-English advice by phone before and after you buy
- Spare parts, salt and servicing support for years after install