Understanding Your Home’s Water System: Mains, Stopcocks, and Storage Tanks Explained

If you’ve ever struggled to find your stopcock during a leak or wondered why your shower pressure drops when someone runs the tap, understanding your home’s water system is more important than you think.

Whether you live in a modern Worcester new build or a period home in Broadway or the Cotswolds, the way your plumbing is set up determines water pressure, heating performance, and even energy efficiency.

Let’s break down the key components — and what every homeowner should know.

What Is a Mains Water Supply?

Your mains water is the fresh, treated water that enters your home from the public supply network. It’s usually controlled by a stopcock, often located under the kitchen sink or near the front door.

Mains-fed systems typically provide high water pressure, ideal for combination boilers and modern mixer showers.

How to Identify Your Stopcock

• Look under your kitchen sink, utility room, or near the front entrance.

• In older homes, it may be outside in a small underground box marked Water.

• Turn it clockwise to close, anti-clockwise to open.

• Always check it works — in an emergency, seconds matter.

What Are Cold Water Storage Tanks?

Older or rural homes — especially Cotswold stone cottages — often use a gravity-fed system with tanks in the loft. These store cold water before it’s fed down to taps and the hot water cylinder.

While this system provides steady pressure even if mains flow is low, it’s not ideal for power showers or high-demand appliances.

Loft Storage Tanks

• Pros

  • Reliable even during temporary mains interruptions

  • Works well with traditional boilers

  • Suitable for multi-storey or older properties

• Cons

  • Lower pressure compared to mains

  • Requires more maintenance (risk of stagnation or leaks)

  • Takes up valuable loft space

Average Water Pressure by System Type

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Upgrading or Maintaining Your Water System

If your home’s plumbing hasn’t been updated in decades, you could benefit from a system conversion — either upgrading to mains-fed or improving water pressure with a booster pump.

Signs You Might Need an Upgrade

• Low pressure at upstairs taps or showers

• Rusty or noisy pipes

• Visible corrosion on tanks or pipework

• Boiler struggling to heat consistently

• Overflow pipes dripping outside

The Bottom Line

Understanding your home’s water system isn’t just about plumbing — it’s about comfort, efficiency, and peace of mind. Knowing where your stopcock is, how your water is stored, and what boiler system you have helps you prevent costly emergencies and plan smarter upgrades.

If you’re unsure what system you have or whether it’s performing efficiently, a professional inspection can save you time — and potentially hundreds in wasted water and heating costs.

Book a Water System Check in Worcestershire or the Cotswolds

Our engineers specialise in heritage homes and modern conversions, helping homeowners balance efficiency with tradition.

• Full system diagnostics and pressure tests

• Tank cleaning, removal, or conversion

• Stopcock replacement and leak prevention

• Boiler and hot water integration checks

📞 Call us today to schedule your inspection
📧 Email for a free quote
🌿 Trusted by homeowners across Evesham, Worcester, Cheltenham, and Broadway