Combi Boiler Prices UK – A Cost Comparison

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If you know your boiler is on the way out or starting to cost a small fortune in repairs, you may be wondering what the cost of a new model will be.

Combi boilers are a popular choice for modern residential properties, due to their small size but high performance and energy efficiency. A new combi boiler installation can range in cost between £500 to £2,800, depending on the boiler make and model as well as additional services chosen such as chemical flushes, or if adaptations to the current system are required.

In this post, we will explore in further detail the typical costs of installing a new combi boiler as well as considerations that may need to be factored in before proceeding.

What is a Combi Boiler?

The first step of replacing an existing boiler or buying a new heating system entirely is to ensure the type of boiler will be suitable for the property and household requirements.

So let’s cover off what exactly a combi boiler is. A combi boiler is a type of boiler that does not require a water tank to be fitted as the boiler heats the water straight from the mains, and therefore is perfect for smaller properties due to the space-saving benefits.

However, combi boilers do require a significant water pressure in order to work effectively on demand, and also the size of the boiler is of significant importance so that it can produce the correct levels of energy and hot water for the property.

Most combi boilers are highly energy-efficient and therefore despite which make or model is chosen, there will likely be savings from reducing the energy usage. However, there are some factors which you may wish to consider between the brands including; the quality of the product and the reliability, the standard product warranty and the availability of replacement parts.

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Why choose a Combi Boiler?

If a combi boiler is suitable for the property and household there are many benefits to this type of boiler such as:

  • Instant hot water – The main benefit of a combi boiler is the instant hot water that is provided, warmed up straight from the mains. Therefore, there is no waiting around for a tank of water to heat, or worse still to run out mid-shower or bath!
  • Space Saving – As we have mentioned, there is no requirement for a water tank with combi boilers and therefore this can result in significant space-saving. Should a current tank be in place within the property, this can be safely disconnected and removed, providing the area for another use such as storage.
  • Energy Efficiency – Combi boilers are one of the most energy-efficient types of boilers and therefore can provide energy savings as well as a reduction in the household’s carbon footprint.
  • Easy to Install and Maintain – As there are no tanks to install, combi boilers can be fitted promptly. In addition, by installing a modern boiler, the maintenance should be minimal and the availability of any replacement parts should be more easily sourced.

Combi-Boiler Sizes and prices

A boiler’s size is measured by the kW output that the boiler produces, and the size needed will depend on the property and household’s requirements. Purchasing the most appropriate boiler is crucial to ensure that it can produce enough heating and hot water for the household whilst not being too big and therefore wasting energy.

As a rough guide, a small property with 1-2 bedrooms is likely to require a boiler size of between 24kW and 27kW, whereas a medium-sized property with 3-4 bedrooms would require a slightly more powerful combi boiler producing 28kW to 33kW. For the larger sized properties, classified as having 4 or more bedrooms, the most powerful combi boilers would be most suited, between 36kW and 42kW output.

As a general rule, the higher the power output of the boiler, the higher the price, although there is a slight overlap of the average costs per size band, depending on the make and model chosen. The typical prices per boiler size are as follows:

  • Size 24kW and 27kW range between £600 and £1,100
  • Size 28kW to 33kW range between £500 and £1,250
  • Size 36kW and 42kW range between £670 and £1,500

It is important to note that the price of installation and any other services such as chemical flushes, extending the standard product warranty or a boiler insurance policy would be added to the prices mentioned above.

As an example, should the property already have a combi boiler in situ and therefore the requirement is to replace a new boiler like for like, in the same location within the property, the installation cost could be expected to be between £550 and £670.

Further reading: 

Top Rated Combi-Boilers

There are many makes and models of combi boiler available on the market these days, however, the quality of the boiler itself and customer services levels provided are not all the same.

It is recommended that plenty of research is undertaken before selecting your choice of make and model of a combi boiler. However, as a starting point you may wish to consider the following three boilers that are currently the most popular combi boilers in the UK:

  • Worcester Bosch Greenstar Highflow CDi – available in either 29kw or 30kW output options
  • Viessmann Vitodens 200 W Combi – This combi boiler comes in three sizes; 26kW, 30kW or 35kW
  • Vaillant EcoTEC Pro Combi – Also available in three sizes: 24kW, 28kW or 30kW

Each of the above models exceeds 80% rating by Which?, the consumer magazine, and a number of boilers within the ranges motioned above have also received recognition within the Which? Best buy combi boiler awards too.

Combi Boiler Prices Summary

In this post, we have explored further what a combi boiler is, the typical costs of a new model and the factors to be reviewed when deciding if a combi boiler is a suitable type of boiler for your property and typical household usage.

We have also discussed the benefits of combi boilers and taken a brief look at the top combi boilers currently available on the market.

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