Is a condensing boiler a combi boiler? 

The short answer to that question is yes. However, there are three different types of condensing boiler:

  • A combi (or combination boiler) which can provide heating and hot water upon demand.

 

  • A system boiler or heat only (sometimes known as a conventional boiler) which both utilise a tank or cylinder for hot water storage.

 

Read on to learn what we really mean by condensing and combi boilers

Is a condensing boiler a combi boiler - Different types of condensing Boilers

Understanding condensing boilers

 

When talking about condensing boilers, we are actually talking about a certain technology where heat that would normally be lost as part of a boiler’s operation, is reclaimed. This is achieved by extracting the heat from flue gases during combustion. A heat exchanger cools these gases below their dew point, causing the water vapour to condense into liquid form. The latent heat released in this process is used to preheat incoming cold water, significantly reducing fuel consumption.


The energy efficiency of condensing boilers is one of their most significant advantages, with efficiency ratings often exceeding 90%. This high efficiency means more of the energy consumed is converted into usable heat, potentially lowering energy bills. Many modern condensing boilers are equipped with advanced controls that adjust performance based on real-time demand, further boosting their efficiency.


Environmentally, condensing boilers contribute to reducing carbon emissions by utilising energy more effectively. This not only decreases greenhouse gas emissions but also reduces the overall demand for fossil fuels, making them a sustainable heating choice.

Understanding combi boilers

 

Combination boilers, or combi boilers, combine central heating and hot water supply into one unit. When you need hot water, the combi boiler heats it directly from the mains supply, eliminating the need for a separate hot water tank. This results in hot water on demand, ensuring convenience and efficiency. 


One of the key advantages of combi boilers is their space-saving design. Without the need for a separate hot water cylinder or cold water tank, combi boilers are ideal for homes with limited space, fitting easily into kitchen cupboards or utility rooms. This compact design is especially beneficial for flats and smaller houses.


Another significant benefit is the immediate availability of hot water. With a combi boiler, there's no waiting for a tank to fill or heat up; hot water is instantly available when you turn on the tap. This immediacy enhances comfort and contributes to energy efficiency, as water is heated only when needed, potentially lowering your energy bills

Comparing condensing and combi boilers

 

Most, if not all, modern combi boilers are, in fact, condensing boilers. Regulations which came into effect in 2005 state that all new and replacement boilers fitted in the UK are required, by law, to be condensing boilers. Given most boilers tend to have a lifespan of around 10 to 15 years, even up to 20 years if they have been well-maintained and serviced, then if you don’t currently have a condensing boiler at the moment, you may in the near future, or opt for an air source heat pump.

Selecting the right boiler for your home

 

Condensing boilers, which includes modern combi boilers, are highly efficient and are designed to lower emissions from your household. 

 
When looking into having a new boiler fitted at your property, there are several key considerations to keep in mind. Start by assessing your heating and hot water needs and whether you have multiple bathrooms. The size of your property is another factor; combi boilers can fit in a cupboard, perfect for smaller properties where space can be limited. Larger properties with high water demands require a system boiler combined with a hot water cylinder.


At Baxi, our high-quality boilers are designed for a range of properties. With maintenance plans and warranties available across our products, you can be sure that we will be on hand to help should you need us.

Related FAQs

What happens at a boiler service?

During a boiler service, your engineer will carry out various checks and inspections, including but not limited to:

 
•    Correct gas pressure and flow
•    Flue and combustion
•    Condition of electrical connections
•    Fans and other key components 
•    Seals are intact
•    Electrodes are in a good condition
•    Safety devices are checked
•    Condensate trap and pipe is not blocked
•    Water and gas pipework

Can I run a bath and shower at the same time?

If you have a cylinder installed, you should be able to run a bath and shower at the same time. If you have a combi boiler, you may notice a drop in performance as the boiler splits the hot water between the shower and the bath.

What are the different types of boilers?

The main types of boilers are: 

  • Combi
  • System
  • Heat only
  • Electric

Learn about the pros and cons of each type here.

Why is my boiler leaking?

If you suspect your boiler is leaking, check for error codes on the appliance, any dampness or dripping, and your pressure level for indications. We also have a range of How-to Guides to help troubleshoot the problem.

Are Baxi engineers Gas Safe registered?

Baxi engineers are all Gas Safe registered and undergo regular training so you can be sure the work they do is safe and at the highest standard.

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