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Updated: April 27, 2024

When it comes to choosing the right boiler for your home or business, the decision between condensing and non-condensing boilers is one that could have significant implications for both your carbon footprint and your wallet. While both types of boilers are tasked with the common goal of heating, the journey they take to get there varies considerably.

Condensing boilers pride themselves on superior energy efficiency, reclaiming heat that would otherwise be lost, leading to reduced heating bills and a more eco-friendly existence. On the other hand, non-condensing boilers enjoy the reputation of being more cost-effective upfront, with a simpler design that avoids the complexities of secondary heat exchanges.

This blog post will delve into the intricate dance of heat, cost, and efficiency, exploring why each of these boiler types could be the cornerstone of your heating system – and how choosing the right one could lead to a seamless harmony of savings and sustainability.

What Is the Difference Between Condensing and Non-Condensing Boilers?

Both condescending and non-condensing boilers burn fuel such as gas or oil. However, condensing boilers are more energy efficient than non condensing boilers. Condensing boilers have an efficiency rate of up to 99%. On the other hand, non-condensing boilers are only up to 78% efficient. 

Condensing boilers can help reduce your energy bills and save you money as well as reduce your carbon emissions. 

If you are replacing an old boiler, keep in mind that it is required by UK law that your new boiler should be a condensing boiler. It is illegal to install a non-condensing boiler in the UK. 

Boilers can last as long as 10 to 15 years. Most boilers installed before 2005 might be non-condensing. If that is so, then it is time for you to upgrade your boiler. A new boiler has the advantage of being efficient and as a result can save you up some money on energy bills. 


What Are the Advantages of Condensing Boilers?

Better efficiency rates

What makes condensing boilers better than non-condensing boilers is the increased efficiency levels offered by condensing boilers. Without condensing technology, a boiler can waste 30% of its heat. This happens because the heat will go straight out of the flue pipe. 

Condensing boilers can achieve a high efficiency level due to using a Flue Gas Heat Recovery System. This system can recycle the waste heat in the boiler’s flue in order to preheat the cold water that is entering your heating system. 

Non-condensing boilers levels of efficiency stand at 78%. Older boilers can achieve yet a lower efficiency rating than non-considering. Old boilers can only achieve 55-65% efficiency levels. Condensing boilers, on the other hand, can reach an efficiency level of 90-99%. 

In conclusion, the more efficient your boiler is, the more money you can save on energy bills. 


Condensing boilers are sealed for heat insulation. They can capture air from the outside of the room they are located in. After that, the air will be released outside through a flue pipe. This method will eliminate the risk of contact with any toxic substances. This is possible due to draining the system via a pipe. 

What is more, condensing boilers are equipped with safety devices. These include thermostats and pressure relief valves which can turn off the boiler automatically when an error is detected. Such devices are not found in non-condensing boilers. 

Reduced carbon footprint 

It has become mandatory for homeowners to install condensing boilers when replacing their old ones. Condensing boilers can reduce carbon emissions. As well as helping the environment, condensing boilers can help your pocket by saving you money on heating bills. 


What are the disadvantages of condensing boilers?

There are some drawbacks to using a condensing boiler. However, the advantages of having a condensing boiler outweigh the disadvantages. 

More Expensive to Maintain

Because of their technical complexity, condensing boilers can be more expensive to maintain. On the other hand, non-condensing boilers are cheaper to maintain. However, condensing boilers have a longer lifespan and better efficiency so they also have the ability to save you money. 

More Complex Systems

In order to operate efficiently, condensing boilers have a more complex internal system. As a result, they might be prone to have more issues. A common issue with condensing boilers is a blocked or frozen external condensate pipe in extremely cold weather. 

What is more, the condensate can lead to corrosion if not well maintained. That being said, condensing boilers are still worth the investment due to their high efficiency. 


How can I choose the best condensing boiler for my home?

When choosing the best condensing boiler for your home, there are some important factors you need to consider. These are things that can help you make the best possible decision. These factors include boiler type, house size, output size, fuel type and cost. 


What is meant by a condensing boiler?

A condensing boiler operates by using condensing technology in order to make the most of the heat it generates. Gases are usually released via a flue when a fuel such as oil or gas are burned. In a non-condensing boiler, these gases are released into the atmosphere and any heating potential they have would be lost. 

What are the different types of condensing boilers?

Three main types of condensing boilers can be found in the boiler market. These include: combi, system and regular boilers. 

What is the difference between condensing and non condensing boilers?

Condensing boilers are a sealed for heat insulation system and they take air from the outside. On the other hand, non-condensing boilers take air from the inside.