What Is a System Conversion? A Complete Guide for Homeowners

Upgrading your heating system is one of the most important investments you can make in your home. One of the most common upgrades we carry out at Wirral Gas is a system conversion — a process that modernises how your heating and hot water work together.

In this guide, we explain what a system conversion is, why it’s done, and the different types available.

What Is a System Conversion?

A system conversion involves changing the type of heating system in your home. This usually means removing parts of the existing system — such as hot water tanks, cylinders, and outdated pipework — and replacing them with a more modern, efficient setup.

It’s not just a boiler swap. A proper system conversion includes:

• Removing old tanks and cylinders

• Altering or replacing pipework

• Installing a new boiler and controls

• Upgrading safety and efficiency components

• Setting up the system for modern use

The result is a cleaner, more reliable, and more efficient heating system.

Why Do Homeowners Choose a System Conversion?

Most homeowners choose a system conversion for three main reasons: efficiency, space, and performance.

1. Improved Energy Efficiency

Modern systems are far more efficient than older setups. Converting can reduce heat loss, lower fuel usage, and help cut energy bills.

2. Freeing Up Space

Old systems often include:

• Loft tanks

• Hot water cylinders

• Airing cupboards

A conversion can remove these, giving you valuable extra storage space.

3. Better Hot Water & Heating Performance

New systems provide:

• Faster hot water delivery

• Better water pressure

• More consistent heating

• Smarter temperature control

  
  

4. Reliability & Safety

Older systems are more prone to leaks, breakdowns, and corrosion. A conversion replaces ageing components with modern, safer equipment.

Common Types of System Conversions

Every home is different, so there isn’t a “one size fits all” solution. Below are the most common system conversions we carry out.

1. System Boiler to Combi Boiler Conversion

This is one of the most popular upgrades.

What it involves:

• Removing the hot water cylinder

• Removing loft tanks (if present)

• Installing a combi boiler

Best for:

• Small to medium homes

• Properties with 1–2 bathrooms

• Homes wanting instant hot water

Main benefit:Hot water on demand with no storage tanks.

2. Regular (Conventional) Boiler to Combi Conversion

Older homes often have “traditional” systems with tanks in the loft and a cylinder in the airing cupboard.

What it involves:

• Removing loft tanks

• Removing hot water cylinder

• Altering pipework

• Installing a combi boiler

Best for:

• Older properties

• Homes undergoing renovation

Main benefit:Complete modernisation of an outdated system.

3. System Boiler with Unvented Cylinder Upgrade

Not everyone wants a combi boiler. Some homes benefit from keeping stored hot water.

What it involves:

• Replacing old vented cylinders

• Installing a sealed unvented cylinder

• Upgrading safety controls

Best for:

• Large homes

• Multiple bathrooms

• High hot water demand

Main benefit:Strong pressure to multiple taps at once.

4. Open-Vented to Sealed System Conversion

Older systems are often “open vented,” meaning they rely on tanks in the loft.

What it involves:

• Removing feed and expansion tanks

• Sealing the system

• Adding pressure controls

Best for:

• Homes with frequent pressure issues

• Systems prone to airlocks

Main benefit: More stable pressure and fewer faults.

What’s Included in a Professional System Conversion?

At Wirral Gas, a proper system conversion includes much more than fitting a boiler.

Our service typically covers:

• Full system assessment

• Safe removal of old equipment

• Pipework upgrades

• System flushing (where required)

• Smart controls installation

• Safety testing and commissioning

• Gas Safe certification

• Full customer handover

This ensures your new system works efficiently from day one.

Is a System Conversion Right for Your Home?

A system conversion may be right for you if:

• Your boiler is over 10–15 years old

• You have poor water pressure

• You want to free up cupboard space

• Your heating is unreliable

• Your energy bills are rising

• You’re renovating or extending

The best way to know is with a professional survey. We assess your water supply, property layout, usage needs, and budget before recommending the right option.

Why Choose Wirral Gas for Your System Conversion?

We’re a local, experienced heating company serving homes across the Wirral and surrounding areas.

When you choose us, you get:

• Qualified Gas Safe engineers

• Expert system design

• High-quality installations

• Extended warranty options

• Clear pricing

• Ongoing aftercare

We don’t believe in “quick swaps” — we deliver properly planned, fully compliant conversions built to last.

Thinking About a System Conversion?

If you’re considering upgrading your heating system, our team is happy to help. You can visit our system installation page for more information on what we can offer.

If you are considering installing a new system at your home or business, please feel free to contact us on 0345 548 4080 – We'd be happy to help.