What is a Condensing Boiler?

A condensing boiler has the ability to collect gas generated by fuel and use it to heat water entering the system.  This makes for a more environmentally friendly option than the old style, non-condensing boiler. These old boilers released significant amounts of harmful carbon emissions (greenhouse gases) into the atmosphere.

Condensing boilers have been mandatory in the UK for new gas boiler installations since Boiler Plus legislation was introduced on 1st April 2005.

How does a Condensing Boiler Work?

Condensing technology makes better use of the heat it generates. When fuel is burned, gases are produced. These gases are released from the flue. Whilst old, non-condensing boilers wastefully release these gases into the atmosphere, condensing boilers capture the gases and recycle them back into the system via the heat exchanger into the primary circuit. Depending on the boiler type, the primary circuit then moves the heat into either the radiators (the heating circuit) , or the domestic hot water supply.

For combi boilers, the hot water is usually heated through a secondary heat exchanger (plate to plate). For heat only appliances, the hot water is stored in a cylinder within the home.

Are Condensing Boilers Cost Effective?

Condensing boilers are considered to be far more cost-effective than non-condensing boilers due to their superior efficiency.  Many new models can reach over 90% efficiency compared to 70-80% efficiency for non-condensing.

Burning less fuel and reducing carbon emissions make condensing boilers the greener, cheaper option for homeowners.

Is a Modern Combi Boiler always a Condensing Boiler?

Yes, all modern boilers, whether they are combi or regular, are condensing boilers. UK legislation banned the sale of non-condensing boilers back in 2005.

*Source: The Committee On Climate Change

What are the Main Advantages of a Condensing Boiler?

A flue gas recovery system has 3 main advantages:

• Reduced fuel consumption
• Better for the environment due to lower carbon emissions
• Lower energy bill spend

How long do Condensing Boilers Last?

The lifespan of a condensing boiler is variable, depending on the manufacturer, model and usage. Annual servicing of your boiler is essential maintenance that will prolong the life of any boiler. Always take care to have this service carried out by a Gas Safe registered heating engineer.

Most quality boiler manufacturers provide a standard warranty of 5-10 years.

How much does a Condensing Boiler Cost?

This is entirely dependent on the type, model, size and manufacturer of the boiler.  It is essential to get the correct size boiler for your needs. Bigger isn’t always better and a huge oversized boiler with a high output will waste money and may even not work properly. Always take expert advice before selecting a boiler.

Other costs that may need to be factored in:

• Relocation of boiler, if needed
• Add-ons such as Smart Controls
• Conversion from say, regular to combi type of boiler

What Size Condensing Boiler do I Need?

Choosing the correct size condensing boiler for your particular home and needs is an important decision. Getting it wrong could prove costly for your pocket and the environment.

You’ll need a boiler powerful enough to heat your home and your water, but not so big that you are wasting energy. Conversely, an underpowered boiler will inevitably prove disappointing when your radiators won’t warm up and you don’t have enough hot water.

Selecting the correct size boiler will depend on the size of your property and the needs of the household. Always discuss your requirements with an experienced boiler engineer before making any purchase decisions. Most modern boilers are now highly efficient, meaning most of us can get away with a smaller boiler.