Should I Swap my Heat-Only Boiler for a Combi?

For years, heat-only boilers, also known as traditional or conventional boilers, were the most common type of boiler system fitted in UK properties – hence their name ‘traditional boilers.’ However, the past few years have seen a new heating preference come to light in the form of the combi boiler.

If you still have a traditional boiler heating system in your home, you’re probably wondering whether you should be out with the old and in with the new by getting a new combi boiler system installed. If this is the case, you’ve come to the right place. 

In this guide, we’ll help you decide whether you should swap your traditional boiler for a combi boiler. We’ll highlight the benefits of both types of systems, provide you with an insight into what the system swap process could look like and also give you an estimate of costs.

What Is A Combi Boiler?

A combi (or combination) boiler is a type of heating system which provides both heating and hot water all through one single unit. These systems are typically compact in size, delivering their hot water supply without any additional tanks or cylinders. They source their water supply directly from the mains.

Combi boilers are now the most popular type of boiler system in the UK, with many favouring them for their energy efficiency, instantaneous hot water, and space-saving benefits.

Heat Only vs Combi – Why Change To A Combi Boiler?

There are plenty of reasons why some homeowners choose to swap their heat-only boiler system for a combi. Granted, traditional boilers do provide a number of benefits, such as their ability to deliver hot water to multiple taps at once and their compatibility with backup immersion heaters. However, there are also a variety of advantages of swapping to a combi boiler. 

These include:

•     Space-saving – Combi boilers do not require a hot water cylinder or cold water tank for storage. They are compact in size and designed to fit into a standard-sized kitchen cupboard. They are therefore a great space-saving option as you won’t have to store any of these extra components in your loft or attic.

•     On-demand hot water – As combi systems do not store their water, they source their supply directly from the mains and can thus provide hot water instantaneously.

•     Energy efficiency – Combi boilers are highly energy efficient. Like all modern boilers, they are built with condensing technology which allows them to recover latent heat from flue gases and reuse this energy to provide further hot water and heating for the system.

•     Cost-effective – Through their high level of energy efficiency, combi boilers can help you save money on your energy bills by reducing your household energy consumption.  According to the Energy Saving Trust, you could save up to 40% on your energy bills by replacing your 12-15-year-old boiler with a brand new A-rated combi boiler.

•     Modern combi boilers have high flow rates – In the past, combi boilers were believed to be a form of heating which was mainly suited to smaller homes with lower hot water demands. However, with advances in technology, many modern combi boilers are built to meet the needs of larger homes with higher hot water requirements. For example, the boiler brand Alpha developed their Flowsmart boiler systems with high flow rates to allow large properties to enjoy the benefits of a combi boiler.

What Happens During A Heat-Only To Combi Boiler Swap?

One factor that you must consider when changing from a heat-only boiler to a combi system is that the installation process is likely to take longer and be slightly more complicated than a simple like-for-like system swap. The process will typically add an extra day to the installation time.

This is due to the modifications to the heating system within the property which must take place. Nevertheless, if a combi system can do a better job at providing you with the heating and hot water you need, then the extra time and effort spent on the installation are more than worth it.

Here’s what a typical heat-only boiler to combi boiler installation will entail:

• Your Gas Safe registered engineer will drain the existing heating and hot water system.
• They will then remove the existing boiler.

• They will also get rid of the thermostat and boiler controls (If required).
• Your engineer will also remove the tanks and cylinders from your old system out of the property.
• They will then convert the traditional heating system to a combi system. This will involve upgrading the gas run to 22mm.
• The installation of the new combi boiler will take place.
• Your engineer will then perform a chemical flush or central heating Powerflush on the entire heating system to cleanse the system and increase efficiency.
• They will also install deaerators and/or magnetic filters.
• Your installer will then fit your thermostat and configure the device to work with the new combi boiler.

How Much Are Installation Costs Of A Combi Boiler? 

Homeowners considering swapping over to a combi boiler should be aware that the installation costs are likely to be higher than they would be for a simple like-for-like system swap. This is because the installation will require additional labour, such as the removal of the storage cylinder and water tank from your attic and loft spaces to fit your new combi boiler. 

Due to this extra work, you can typically expect to pay between £2,200 – £2,500 to replace your heat-only boiler system with a combi boiler. The process usually takes around two days to complete.

Do I Need Boiler Cover? 

So, after learning about the process of swapping your heat-only boiler with a combi boiler, could this be a suitable option for you? If so, there are many boiler manufacturers on the market that could provide you with a top-quality combi boiler. 

Popular combi boiler brands include Worcester Bosch, Ideal, Vaillant, Viessmann and Alpha.

If you decide to get a combi boiler installed into your home, it is essential that you get protection for your heating system, just in case of a boiler breakdown or fault. Getting boiler cover is one of the most effective ways of protecting your home heating system, as it helps to ensure that your boiler is covered even after its warranty period has ended.

Take a look at our boiler cover options or for more information on boiler cover, get in touch with us today.