What is a condensing boiler?

How does a condensing boiler work?

Condensing boilers are a new generation of boilers designed with energy efficiency and home comfort in mind. Latest-generation condensing technology allows these types of boilers to provide effective heating for your home, while saving energy compared to their conventional counterparts.

To heat up your home and ensure a steady supply of hot water, condensing boilers work differently to conventional boilers. In the process of heating your home, a conventional boiler releases both water vapour and smoke into the atmosphere.

That isn’t the case with condensing boilers: instead, these boilers recapture this water vapour that conventional boilers release as waste gas. Condensing boiler models condense this water vapour to liquid water, extracting additional latent vaporisation heat as it does this. That makes condensing boilers far more energy efficient when compared to conventional boilers; a great choice for heating your home in a way that best protects the environment.

Combi boilers

Combination - or combi - boilers heat your home and heat hot water for your household at the same time. This will likely be the case with any condensing boiler you choose to install in your home.

Oil, gas, wood: condensing boilers are suitable for all types of fuel

These heating systems can operate using a variety of fuel types, including oil, gas and wood. Your condensing boiler will simply adapt its heating circuit to suit the type of fuel you choose to use to heat your home.

You can also connect your condensing boiler up to a solar water heater, increasing energy efficiency by having the sun’s natural power contribute to heating your home.

As mentioned above, condensing boilers produce heat in a two-fold process, increasing their energy efficiency in comparison with conventional boiler options. In phase 1, the condensing boiler will burn whichever fuel you’ve chosen to use to heat your home (be that gas, oil or wood, for example). That heats your home and home water supply in the same way as a conventional boiler would.

Phase 2 is what sets condensing boilers apart from conventional models. Rather than letting combustion fumes and water vapour escape into the atmosphere as under-utilised waste gases, condensing boilers cool these gases down, condensing them to utilise their thermal energy content.

This process maximises energy saving, putting condensing boilers among the most energy efficient boiler options you can install in your home.

Preheating hot water in your home radiators

Condensing boilers have another significant advantage over conventional boilers: these boilers use the condensation phase to preheat the water in your home radiator system.

The waste water vapour’s thermal energy is used in your home central heating system, meaning less energy is required to keep your home at the perfect temperature.

What are the key differences between floor-standing and wall-mounted condensing boilers?

With condensing boilers, you’ll have the option of a floor-standing or wall-mounted installation. The option you choose will ultimately depend on the type of space in which you need to install your new condensing boiler; that will depend largely on where it’ll be situated within your home.

Wall-mounted condensing boilers don’t take up much space, so might suit an in-kitchen installation. If you opt for a floor-standing condensing boiler, it’ll be best suited to an installation in the basement or garage of your home.

When it comes to choosing how to install your condensing boiler, there are a few key points to bear in mind:

• Whichever installation type you choose for your condensing boiler, you’ll also need to be able to install an exhaust flue and smoke duct
• Wall-mounted condensing boilers can be slightly cheaper to purchase
• Oil-fuelled condensing boilers must be floor-standing

What are the advantages and disadvantages of a condensing boiler?

Key advantages

• Limited heat and energy loss - high energy efficiency
• Up to 30% savings on your home heating bill
• Lower gas consumption that conventional gas boilers - 10-25% less gas consumption for the same level of heat production
• Quick and simple installation, with multiple installation options to suit every home
• Combi boiler for central heating and hot water for the home
• Better for the environment - lower CO2 emissions compared to conventional boiler options

Key disadvantages

• Slightly more expensive than conventional gas, oil or wood boilers - around 30% cost increase
• Must install an exhaust flue and smoke duct to ensure safe home heating

Condensing boilers: energy efficient and cost-effective home heating

Studies indicate that it’s possible to save up to 25-30% on your home energy usage with a condensing boiler. That’s better for the environment and better for your home heating costs!

Condensing boilers are up to 105-110% more efficient than conventional boiler models when it comes to central heating and heating your home’s hot water. That’s why they’re currently slightly more expensive outright than conventional boilers.

However, given condensing boilers’ improved energy efficiency, you might be eligible for reduced VAT on the purchase. That, in combination with the energy savings you’ll make once your new condensing boiler is installed, means condensing boilers are a profitable investment for your home heating.