Hard water and limescale: what it does to your plumbing
Surrey, south London and much of the surrounding area sit on chalk, so the mains supply is hard. Dissolved calcium deposits as scale wherever water is heated or moves through a restriction — immersion elements, cylinder coils, combi heat exchangers, shower cartridges and tap mechanisms — reducing flow and shortening component life.
Key facts
- Region
- Surrey, south west London and Sussex supplies are hard
- First to fail
- Shower cartridges, tap mechanisms, immersion elements, cylinder coils
- Practical fixes
- Descaling, replacing scaled components, sensible temperature settings
- Not offered
- Water softener supply and installation
Signs of scale damage
| Symptom | Most likely cause |
|---|---|
| Shower flow drops gradually over months | Scale in the head and cartridge. |
| Kettle and taps furring quickly | Normal hard-water deposit — a marker of what is happening inside the system. |
| Hot water slower to reheat | Scale on the cylinder coil or immersion element. |
| Noisy boiler or cylinder (kettling) | Scale on the heat exchanger surface. |
Where scale actually does the damage
Scale forms fastest where water is hottest and where it passes through small openings.
- • Immersion elements and cylinder coils — the insulating layer makes heating slower and eventually burns elements out.
- • Combi heat exchangers — restricted flow shows up as fluctuating hot water temperature.
- • Shower valves and cartridges — sticking temperature control and reduced flow.
- • Tap mechanisms and aerators — drips and weak flow from grit and deposit.
- • Toilet fill valves — slow or noisy filling and running overflows.
What actually helps
Nothing removes hardness from the mains except treatment. What varies is how much protection each option buys and what it costs to run.
- • Descaling components during a service rather than replacing them once they fail.
- • Setting the hot water thermostat sensibly — higher stored temperatures scale faster.
- • Regular cleaning of aerators, shower heads and fill valves, which is free and often enough.
- • Scale-reduction devices, which vary widely in effectiveness — ask what a specific device is actually claimed to do before buying it.
What we do not currently offer
We do not install water softeners at present. If softening is what you need, we will say so rather than sell you something else, and we can still deal with the scale-related repairs on your existing system.
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We cover the GU, KT, SW, CR, RH and BN postcode areas, 24 hours a day, 7 days a week, including bank holidays.