Hot Water Cylinder Replacement With New Combi Boiler

Replace your old hot water cylinder with a modern, energy-efficient combi boiler for free through ECO4 scheme. Learn how to get a free upgrade via ECO4 scheme.

hot water cylinder

Hot water cylinders are commonly found in older heating systems. They store heated water in a tank, which takes up space and leads to energy loss through heat dissipation. These old systems are slower, less responsive, and often result in higher energy bills.

Switching to a modern combi boiler removes the need for storage tanks, giving you instant access to hot water, better efficiency, and more room in your home. It’s an ideal upgrade if you want to modernize your heating system and cut running costs.

What Is A Combi Boiler?

A combi boiler, short for “combination boiler,” is a compact unit that provides both heating and hot water directly from the mains. It eliminates the need for a seprate hot water cylinder or cold water storage tank, making it ideal for smaller homes, flats, and properties with limited space.

Modern combi boilers are designed for efficiency and convenience. They heat water on demand, reduce energy waste, and support smart heating controls for remote management and automation.

Combi Boiler vs Cylinder System

Unlike conventional boilers, which store hot water in advance, combi boilers deliver it instantly. This key difference results in:

  • Lower energy use, since water is only heated when needed
  • Faster access to hot water at mains pressure
  • Simplified installation with less pipework
  • Freed-up loft or airing cupboard space

These benefits make combi boilers an attractive choice for energy-conscious homeowners looking to optimize their living space.

How Much It Cost To Replace A Hot Water Cylinder With Combi Boiler?

The typical cost of replacing a hot water cylinder and boiler system with a combi boiler ranges between £2,500–£4,000, depending on the property size, boiler model, and installation complexity.

However, under the ECO4 government grant scheme, many UK homeowners can receive a brand-new combi boiler completely free of charge. This includes full installation, removal of the old system, and new boiler testing.

What Is The ECO4 Scheme?

​The ECO4 Scheme is a UK government initiative that helps low-income and fuel-poor households improve energy efficiency through fully funded upgrades. You may be eligible for a free boiler replacement if:

  • Your current boiler is over 15 years old.
  • Your home has an EPC rating of D, E, F, or G.
  • You receive qualifying benefits (Universal Credit, Pension Credit, Income Support).
  • You own your home or rent privately (with landlord permission).

You can check eligibility and apply through Cozyfy’s approved Eco provider.

How Cylinder To Combi Replacement Works?

The upgrade process is straightforward and handled by Cozyfy’s certified engineers:

  1. Eligibility Check: Complete Cozyfy’s online form within 60 seconds and apply for your grant.
  2. Home Survey: Schedule a free assessment of your existing heating system with Cozyfy’s qualified engineers. 
  3. Approval: Receive confirmation of your free boiler grant by Cozyfy after home assessment.
  4. Installation: Your old hot water cylinder and boiler are removed and replaced with a new combi boiler, typically within 1–2 days.
  5. System Test & Handover: Cozyfy’s engineers test the new system and provide a full user guide.

Benefits Of A Combi Boiler

Switching to a combi boiler comes with a long list of practical benefits:

  • You free up valuable indoor space by removing old storage tank.
  • Heating becomes more efficient, reducing your monthly bills.
  • You enjoy strong, fast-flowing hot water with no wait times.
  • The system requires less maintenance and is easier to manage.

Modern combi boilers also help lower your carbon footprint and boost your home’s EPC rating, making your property more valuable and environmentally friendly.

Recommended Combi Boilers For UK Homes

At Cozyfy, we work with leading brands known fortheir performance and reliability:

  • Worcester Bosch Greenstar 4000: A-rated, efficient, and whisper-quiet.
  • Ideal Logic+: Affordable, compact, and easy to install.
  • Baxi 800: Durable and backed by a long warranty.
  • Vaillant ecoTEC Plus: Reliable and compatible with smart controls.

All boilers installed through ECO4 scheme are A-rated, Gas Safe certified and according to industry standards.

Final Thoughts

Replacing a hot water cylinder with a combi boiler is one of the best upgrades you can make for energy savings, comfort, and home efficiency. With the help of the ECO4 scheme, many UK households can now complete this upgrade for free.

Cozyfy makes the process simple, handle your application, survey, and installation from start to finish. Enjoy a warmer, more efficient home with no upfront costs.

Apply Today At Cozyfy

Frequently Asked Question!

A hot water cylinder stores and heats water for use in taps, showers, and baths. It fills with cold water, which is then heated either by a boiler or an electric immersion heater, and keeps the hot water ready for use when needed.

You can replace a hot water cylinder with a new combi boiler under ECO4 scheme. For a hassle-free upgrade, visit Cozyfy website and apply for your grant today.

A combi boiler is a compact unit that provides both central heating and hot water on demand, directly from the mains without the need for a hot water cylinder or storage tank.

A combi boiler usually costs between £1,500 and £4,500 with installation. Prices vary based on brand, home size, and system complexity.

Yes, under ECO4 scheme you can get a free combi boiler if you meet the eligibility criteria, you can get a combi boiler for free.