Combi boilers are space-saving options for heating your home and are considered to be some of the best boilers in the UK. They consist of a single compact unit capable of both running your radiators and providing your taps and showers with hot water. Their high functionality —alongside the modern technology they incorporate— has made them the most commonly installed type of boiler in the UK.
If you are looking for a new boiler, considering a new combi is a must. You’re probably asking yourself “but what are the best combi boilers in the UK and how do I choose one?” Given their popularity, the market is full of options so finding the best combi boiler for your house could become overwhelming. In this article, we will share with you tips, lists, and the best combi boilers reviews that will make your search easier.
Are you interested in a combi boiler? GreenMatch can help you find the best boilers on the market that best meet your needs. We will save you hours of going through countless product pages thanks to our team of experts and our nationwide network of partner installers. Ask for quotes now, and we will send you up to 3 tailor-made quotes for free. You are not obliged to accept any of them.
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With so many models available, there is not just one best combi boiler suiting all needs. It is more accurate to say that when it comes to the best combi boiler (and other central heating boilers), the best buy for you is the one that best meets your house requirements and your budget.
There are, however, a few things you can look at when looking for the best combi boilers. Here we share the essential ones with you. We have also covered them in our best combi boilers reviews throughout this article.
To help you find the best combi boilers, we’ve listed the top 5 boiler manufacturers in the UK market:
Each of these brands has been in the boiler production business for decades. Besides their products’ reliability, customer service ratings, great warranties, and excellence awards, they invest in future-proofing and increasing the efficiency of their boilers.
Greenstar 8000 Style combi
Baxi Platinum combi
ecoTEC exclusive with Green iQ combi
Vogue Max combi boiler
Vitodens 200-W combi boiler
Gas boilers are the most popular choice among UK homeowners. Figures show that approximately 85% of homes in England, Scotland, and Wales are connected to the gas network and use a gas boiler. As combis are the most common type of boiler across the country, it doesn’t come as a surprise that there are many gas combi boilers around.
For those houses disconnected from the grid, oil or liquefied petroleum gas (LPG) are the most common options for fueling their boilers. Electric boilers are another alternative, though they are expensive to run due to the high electricity prices in the UK.
Gas combi boilers run on natural gas sent to homes via the national gas grid. Even though natural gas is produced from fossil fuels, it is considered cleaner than oil and coal.
Although they release CO2 into the atmosphere when running, modern gas combi boilers have inbuilt condensing technology. Because the condensing boiler efficiency is very high, they can help you keep your energy bills low and reduce your carbon footprint.
Oil combi boilers are a cost-effective alternative for houses disconnected from the grid. However, you will need to store the fuel in an external tank. This makes them less space-saving than gas and electric combis. The best oil combi boilers available on the market also have inbuilt condensing technology.
LPG is a combined product of natural gas and oil extractions. The best gas combi boilers are usually compatible with LPG. This makes them suitable for properties connected to the grid as well as for the disconnected ones.
Electric combi boilers don’t waste energy or release CO2 when working. However, they can only achieve a zero-emissions performance as long as the electricity powering them comes from renewable sources. For instance, you could power them using solar panels.
The best electric combi boilers don’t waste energy at all, as they boast efficiency ratings of 100%. Nevertheless, they are very expensive to run.
From an environmental perspective, we can draw some conclusions on the environmental impact of each type of combi boiler based on the fuel they use.
|Emission Intensity by Fuel (kilograms of CO2 equivalent per kWh)|
England, Scotland and Wales
* Generated using fossil fuels and distributed through the national grid
At GreenMatch, we are committed to helping you navigate the transition to more sustainable ways of heating your home. Looking at the table above, we suggest switching to low-carbon systems such as solar panels in the UK, heat pumps, or biomass boilers. However, these are still rather expensive alternatives.
If you are not ready yet to switch because of either technical or financing reasons, consider installing a highly-efficient electric or gas combi boiler. Our experts can send you up to 3 free offers for these energy-efficient solutions from suppliers near you to help you find the best boiler in 2023.
We advise you then compare these offers objectively to lock in the best deal. For instance, in a gas-heated home in England, Scotland or Wales, you could save up to £840 per year on your energy bills by installing a highly-efficient condensing combi boiler. Get started by clicking the button below.
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Simple and straightforward: the best combi boiler for your house is the one that best meets your house’s needs. In this regard, it is essential that you get a combi boiler as powerful as the size of your house requires it. Otherwise, your combi will struggle or fail to cope with the heating and hot water demand.
|Approximate Combi Boiler Sizes (CH Output)|
Combi Boiler Size
Houses with up to 10 radiators (usually up to 4 bedrooms)
Houses with 10-15 radiators (usually 4 to 5 bedrooms)
Houses with 15-20 radiators (usually 5-7 bedrooms)
Naturally, a much less powerful combi boiler will be enough for a small flat with 1 bedroom.
A combi boiler is probably the best choice for a 3-bed house, as you won’t need it to be too powerful. You have several good options here, including gas and electric boilers. In addition to the models mentioned above, you can consider the Electric Heating Company Mercury combi boiler.
Most likely, the best combi boiler for a 4-bedroom house will have an output rating of around 25kW to 30kW, as 4-bed homes usually have between 10 and 15 radiators. You will also need to take the number of bathrooms into account as well. Check the best combi boiler models in our article on the best boilers for a 4 bedroom house.
Combi boilers are best recommended for small to medium-sized homes as, generally, they are not powerful enough to meet large houses’ demands for heating and hot water. However, there are some models that can cope with it and even do an excellent job.
You can find what is the best combi boiler for a large house in our article on the best boiler for a large house.
Electric combi boilers easily win this division. Their 99-100% efficiency rating is no match for even the most efficient gas or oil condensing boilers. In this regard, our pick for the best energy-efficient combi boiler is the Electric Heating Company Mercury combi boiler.
This boiler is available in a wide range of outputs to suit different property sizes and sports some state-of-the-art features too.
Just be aware that the models with lower outputs cannot produce a high enough flow rate of hot water to efficiently fill a hot bath. They are recommended for use with showers.
When it comes to compactness, combi boilers have no rivals. They are the most space-saving boilers because they don’t require additional components such as hot water storage cylinders or feed tanks. These are our picks for the list of best small combi boilers.
Worcester Bosch Greenstar CDi Compact
Ideal Logic Max Combi
Baxi 800 Combi
Based on our research, the 5 best gas combi boilers are the Worcester Bosch Greenstar 2000, Vaillant ecoFIT Pure 825, Ideal ESP1, Baxi 200 series, and Viessmann Vitodens 050-W.
We have provided a breakdown of their prices below:
|Combi boiler model||Price (excl. installation)|
|Worcester Bosch Greenstar 2000||£730 – £850|
|Vaillant ecoFIT Pure 825||£907|
|Ideal ESP1||£714 – £770|
|Baxi 200 series||£549 – £572|
|Viessmann Vitodens 050-W||£800|
These combi boiler costs above are well-suited if you’re looking to buy a combi boiler on a budget. It’s important to keep in mind that these prices are guidelines and there are a lot of factors that can determine the price, such as the manufacturer, model, fuel type, and output rating.
If you are on a limited budget but want to get the best possible option, we recommend you check the models below. They are the best combi boiler under £1000 we’ve found after analysing dozens of options. These boilers are manufactured by top brands and will provide the best value for their price.
Worcester Bosch Greenstar 2000
Vaillant ecoFIT Pure 825
Baxi 200 series
Viessmann Vitodens 050-W
In addition to the upfront cost of a combi boiler, you have to consider installation costs. On average, boiler installation costs in the UK range from £1,600 to £3,500. The two main factors affecting the cost are:
So, how do you find the best boilers in 2023? Probably the most practical way to get the best deals on combi boilers is trying to reduce installation costs as much as possible. You can easily do this by finding and comparing quotes from different heating engineers in your local area.
Once you get those, you can compare them, check prices and special offers, and see which is the best combi boiler meeting your requirements and budget.
Whilst efficient, this method has a downside: researching and sorting options among dozens of suppliers will take you several hours of your time. You will also have to go through hundreds of customer reviews and verify installers’ credentials in order to find the best boiler in the UK.
However, this is something we are ready to help you with. At GreenMatch, we work with a network of accredited heating engineers across the UK. Fill out our simple form, and we will send you up to 3 free quotes from installers in your area. You are not obliged to accept any quote you receive.
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