💧
⭐ EssentialWater Supply & Storage
How Mains Water Reaches Your Home
Understanding how your water supply works helps you diagnose problems faster and describe them accurately to a plumber or water supplier.
🔍 The journey from street to tap
Water travels from the water company's main (under the street) through a service pipe into your property. At the boundary there is an external stopcock — the water company's responsibility. From there, the service pipe runs to your internal stopcock (your responsibility), usually under the kitchen sink.
🏠 Mains fed vs tank fed
Mains fed (modern): All cold outlets receive cold water directly from the mains. Consistent pressure throughout.
Tank fed (older): A cold water storage tank in the loft feeds bathroom cold taps and toilet cisterns. The kitchen cold tap is always mains fed. Tank-fed systems have lower pressure in bathrooms — this is normal.
🚰 Always drink from the kitchen cold tap
The kitchen cold tap is always direct from the mains and safe for drinking. Bathroom cold taps on tank-fed systems draw from the loft tank and are not recommended for drinking.
Useful when diagnosing problems: "My bathroom cold tap has low pressure but the kitchen is fine" means different things on mains-fed vs tank-fed. On tank-fed, lower bathroom pressure is normal.
Was this helpful?
General guidance only — not a substitute for professional advice. Always consult a qualified engineer if you are unsure. Gas work must only be carried out by a Gas Safe registered engineer. Unvented (pressurised) hot water systems must be worked on by a G3-qualified engineer. We accept no liability for any loss, damage, or injury arising from the use of this information.
Up next in Water Supply & Storage
The Cold Water Storage Tank