Hot Water Cylinders

Why Choose SEAL?

A Cylinder Installation Done Properly, Not Just Quickly

An unvented cylinder is a pressure system, so the quality of the installation matters. We don’t just swap the cylinder and leave — we check the mains supply, safety controls, discharge route, pipework layout and final performance so the system is safe, tidy and built to last.

Pressure Checked First

We check your mains pressure and flow before recommending a cylinder, so you don’t pay for a system that your home can’t properly support.

G3 Safety Focused

Unvented cylinders need the right safety valves, controls and discharge pipework. We install and commission everything correctly.

Tidy Professional Finish

Pipework layout, access for servicing and neatness all matter. We aim for an installation that works properly and looks right.

Clear Handover

We explain how the system works, what to look out for, and provide clear advice on servicing and future maintenance.

Cheap cylinder installs can become expensive later.

Poor discharge pipework, incorrect controls, undersized cylinders or rushed pipework can lead to poor performance, call-backs and safety issues. Our goal is to fit the right system the right way — with honest pricing and no hidden extras.

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Installation Options

Choose Your Cylinder Package

Clear unvented cylinder options to suit different homes, hot water demand, and budgets.

Essential Replacement

Typical Price £1,595

Recomended Cylinder : Joule Invacyl

Ideal if you already have a hot water cylinder and simply need a modern replacement.

  • New quality unvented cylinder
  • Removal & disposal of old cylinder
  • New expansion vessel
  • G3 safety controls
  • Minor pipework alterations
Ask About Essential
Most Popular

Premium Replacement

Typical Price £1,995

Recomended Cylinder : Joule Cyclone Platinum

A complete premium replacement with upgraded safety controls, smarter monitoring and a cleaner installation.

  • Everything in Essential
  • Premium Joule Cyclon cylinder
  • Smart Tundish Alarm
  • Pipework tidy-up
  • Full system health check
  • Premium installation finish
Ask About Premium

Full System Upgrade

Typical Price £2,595

Upgrade From Traditional Gravity-Fed Hot Water System

Replace your old vented cylinder and loft tank with a modern mains-pressure unvented hot water system.

  • Everything in PREMIUM
  • Removal of loft cold water storage tank
  • Removal of existing vented cylinder
  • New Premium Joule Cyclon cylinder
  • Premium installation finish
Ask About System Upgrade

We believe pricing should be simple and transparent. Our advertised prices reflect what most customers pay for a standard installation, and no VAT will be added on top. If your installation requires any additional work or you choose a different model or optional upgrades, we'll explain everything clearly and provide a fixed quotation for your approval before any work begins.

Frequently Asked Questions

Everything You Need to Know Before Installing an Unvented Cylinder

Buying a new hot water cylinder is a significant investment. Below are the questions we're asked most often by homeowners considering an unvented cylinder installation.

An unvented hot water cylinder stores water under mains pressure instead of relying on a cold water storage tank in the loft. This provides stronger showers, faster-filling baths, consistent hot water throughout your home, and can improve the overall efficiency of your hot water system.

Most homes are suitable, but we always check your mains water pressure and flow rate before recommending a system. If your water supply isn't suitable, we'll explain the available solutions. If you decide not to proceed, SEAL advice and quotes are completely free, with no obligation.

The price depends on the cylinder size, brand and whether you're replacing an existing cylinder or upgrading from a traditional gravity-fed system. Take a look at our cylinder packages for guide pricing. We work hard to keep our prices competitive without compromising on quality, and every quote is fixed with no hidden extras, so you'll know exactly what you're paying before work starts.

A straightforward cylinder replacement is usually completed within one day. Larger projects, such as converting from a vented system or relocating the cylinder, may take longer. We'll always give you a realistic timescale before work begins.

Yes. Manufacturers recommend annual servicing to ensure all safety devices continue operating correctly. Regular servicing also helps maintain efficiency, extends the life of the cylinder and protects your manufacturer's warranty.

In many cases, yes. We can remove the existing hot water cylinder and cold water storage tank, then install a modern mains-pressure unvented system. We'll first confirm that your property's water supply is suitable.

We believe quality comes first. Every installation is carefully planned, neatly installed and fully commissioned before handover. We explain how your new system works, leave your home clean and tidy, and only recommend work that's genuinely needed.

Yes. We offer free, no-obligation quotations across Suffolk and North Essex. We'll assess your existing system, explain the available options and provide a clear written quotation with no hidden costs or sales pressure.
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