Energy costs rose dramatically in the UK in 2022. Whilst this is not news for you as a UK homeowner, the impact on your finances will become more and more noticeable as summer ends and fall and winter approach. Higher gas and electricity prices mean higher heating bills, especially for owners of 4-bedrooms or larger houses.
If this is your case, improving your house's energy efficiency before the coldest months of the year arrive is a strategic move.In this regard, replacing your old, inefficient boiler with a new boiler could save you hundreds of pounds. It is simple: new condensing boilers use less fuel than old boilers, so you will spend less money to heat your home.
However, with so many options available on the market, you may wonder which is the best boiler for a 4-bed house. Don't worry, you will find the answer in this article and can already get your best deal by clicking the button below.
First, we need to point out that boiler size refers to the boiler’s power rather than its dimensions (length, width, and height). Any boiler’s technical specification sheet will state it as ‘output rating’, measured in kilowatts (kW). This is they key factor to consider when asking yourself ‘What size boiler do I need for my house?’.
A 4-bed house needs an accordingly powerful boiler, should it be combi, system, or regular. For example, boilers with a lower output rating are sufficient for smaller apartments with up to 10 radiators. However, a 4-bedroom home would need a bigger boiler as these dwellings usually have 10-15 radiators. If your home has less than 10-15 radiators, you can also take a look at our best combi boiler for a 3 bed house guide.
The best combi boiler for a 4-bedroom house will have a maximum central heating (CH) output of 26kW to 32kW and a domestic hot water (DHW) output between 30kW and 33kW, approximately. The maximum CH output rating of the best system and regular boilers for a 4-bed house ranges from 18kW to 26kW.
In all cases, the higher the CH output rating, the more radiators the boiler can run. It may be helpful for you to know that combi boilers have two output ratings: one for central heating and another for domestic hot water. This is because they don't store hot water in separate cylinders and, therefore, have to heat it on demand.
System boilers and regular boilers, on the other hand, have just a CH output rating. Unlike combis, with a system or regular boiler, your domestic hot water will come from a hot water storage cylinder that these types of boilers include.
This difference in how they work is why combi boilers generally need to be more powerful than regular and system boilers to achieve similar heating results.
How many kW does a boiler need for a 4-bedroom house?
Besides the property's size and the number of radiators, other factors can also affect the optimal size of the best boiler for a 4-bed house. For instance, the insulation, number and type of windows, and construction materials can make a difference.
Below, we have included a table with approximate boiler power (kW) ranges meeting the central heating requirements of different house sizes.
Approximate Boiler Sizes (CH Output)
Combi Boilers
System Boilers
Regular Boilers
Houses with up to 10 radiators (usually up to 4 bedrooms)
24-27 kW
9-18 kW
9-18 kW
Houses with 10-15 radiators (usually 4 to 5 bedrooms)
28-34 kW
18-26 kW
18-26 kW
Houses with 15-20 radiators (usually 5-7 bedrooms)
35-42 kW
26-40 kW
26-40 kW
This table gives you a general idea of what size boiler you need for a 4-bed house. However, you should contact a heating engineer to get customised advice based on your house's specific features and fit the boiler that best meets its needs.
Searching for quotes from heating companies near you can take a lot of time and effort, and, if you pick the wrong one, can leave you with a hefty bill to pay. Fortunately, this is something we can help you to avoid.
Click on the button below, and we will find up to 3 quotes from Gas Safe, and OFTEC registered engineers in your area so you can pick the best deal. It's free of charge, and you are not obligated to accept any of the quotes you receive.
Most likely, a 4-bedroom house will also have more than 1 bathroom. The best boiler for such a house will probably be a system one.
Combi boilers generally work better in homes with just 1 bathroom, as they do not store hot water. As a result, the hot water flow may weaken if two showers or taps are used simultaneously. Nevertheless, a high flow combi boiler are powerful enough to meet the hot water demand of houses with 2 bathrooms.
Regular boilers can also heat a 4-bed house. However, you better consider a new regular boiler only if you already have one of those installed in your home. Besides hot water storage cylinders, they need water feed tanks in the loft and extra pipework. Consequently, installation time and costs are likely to increase.
Systems boilers are modern, more compact versions of regular boilers. Instead of a tank in the loft, they take water from the mains. They also include a hot water storage cylinder, making them less space-saving than combi boilers but more capable of supplying hot water to multiple bathrooms and taps at the same time.
Not sure which boiler is best for your 4-bedroom home? Compare them further in Combi vs System Boilers.
We've also created a list of the best boilers for a 4-bed house to help you in your search. It includes combi, system, and regular boilers from top brands:
All boilers listed are powerful enough to heat between 10 and 15 radiators. However, besides their output rating, we also considered other factors when researching and analysing different models available on the market.
The box below will give you an overview of what to take into account when looking for the best boiler for a 4-bed house.
What is the best combi boiler for a 4-bed house?
There are many combi boilers suitable for 4-bed houses. We came up with the following top choices. The first two models in the list are among the best combi boilers for a 4-bedroom, 2-bathroom house. The third one is best suited for homes with 1 bath. Keep in mind that price ranges below are only estimates, not exact quotes.
Baxi EcoBlue Advance Combi 33
The EcoBlue Advance 33 is a highly-efficient gas combi. Baxi designed it for wall-mounted installation.
Size (output rating). A 33kW DHW output rating makes this a suitable boiler for properties with 1-2 bathrooms. It also has a CH maximum output rating of 29.6kW, excellent for a house with around 15 radiators.
Efficiency. The Baxi EcoBlue Advance Combi 33 has an efficiency rating of 93%. It also boasts an ErP A-rating for heat and hot water. This boiler can help to lower your heating bills.
Warranty/Guarantee. Its 10-year standard warranty will give you peace of mind that you have got a resistant and durable boiler.
Price. Its typical total price (including VAT, installation cost, and fittings) ranges from £2,205 to £2,705.
Worcester Bosch Greenstar 8000 Life 30kW
The Greenstar 8000 Life 30kW combi gas boiler is a gas boiler designed by Worcester Bosch, one of the leading boiler manufacturers in the UK.
Size (output rating). Its CH output of 30kW and DHW output of 30.2kW mean that the Greenstar 8000 Life 30kW combi is best suited to homes with up to 15 radiators and more than 1 bathroom.
Efficiency. This is a highly-efficient boiler, as its 94% efficiency and ErP A-rating for heat and hot water show. You can save money on your energy bills all year round.
Warranty/Guarantee. The standard warranty on the Greenstar 8000 Life 30kW combi is 5 years. It can be extended to 12 years when installed by a Worcester Bosch accredited installer.
Price. Its typical total price (including VAT, installation cost, and fittings) ranges from £2,000 to £2,500.
Ideal Vogue Max C32
The Vogue Max C32 is a condensing combi gas boiler designed by Ideal for wall-mounted installation.
Size (output rating). The Vogue Max C32 has a CH output of 26kW and DHW output of 32kW. It can run 15-20 radiators and is suitable for homes with one bathroom that has a bath.
Efficiency. The Vogue Max C32 is a highly-efficient boiler with an efficiency of 93% and an ErP A-rating for heating and hot water. It can help you save money on your energy bills.
Warranty/Guarantee. It has a 10-years warranty as standard. It can be extended to 12 years if installed, and later serviced, by an Ideal Max Accredited installer.
Price. This boiler's typical total price (including VAT, installation cost, and fittings) ranges between £2,006 and £2,506.
What is the best system boiler for a 4-bedroom house?
As we mentioned, a system boiler is probably the best boiler for a 4-bedroom, 2-bathroom house. These are our top picks. Note that the prices expressed below are just estimates.
Ideal Logic Max S24
The Logic Max S24 system gas boiler is a highly reliable condensing unit that boasts 94% efficiency. It is designed and manufactured by Ideal.
Size (output rating). This boiler has a CH output rating of 24.2kW. It is suitable for medium-sized properties with between 10 and 15 radiators.
Efficiency. The Logic Max S24 is a great choice for lowering your energy bills thanks to a 94% efficiency and ErP A-rating for heat.
Warranty/Guarantee. This boiler is available with a standard warranty period of 10 years.
Price. Its total price (including VAT, installation cost, and fittings) will likely lie within the £1,849 – £2,349 range.
Vaillant ecoTEC plus 624
Vaillant's ecoTEC plus 624 is a highly-efficient system boiler that can help lower your energy bills.
Size (output rating). It has a CH output rating of 24.4kW. It is well suited to homes with around 15 radiators.
Efficiency. The ecoTEC plus 624 is a highly-efficient boiler thanks to its heating efficiency of 94% and ErP A-rating for heat.
Warranty/Guarantee. Its 5-year standard warranty can be extended to 7 or even 10 years when installed by a Vaillant Advance installer.
Price. Its typical total price (including VAT, installation cost, and fittings) ranges from £2,027 to £2,527.
Baxi 818
This is a condensing system gas boiler manufactured by Baxi. It is designed for wall-mounted installation.
Size (output rating). Its CH output rating of 18kW makes this boiler work well in properties with up to 15 radiators.
Efficiency. This is a highly-efficient boiler. It features a seasonal efficiency rating of 93% and an ErP A-rating for heat.
Warranty/Guarantee. Baxi 818 boilers come with a 7-year warranty as standard.
Price. Its total price (including VAT, installation cost, and fittings) will likely be between £1,713 and £2,213.
What is the best regular boiler for a 4-bed house?
Regular boilers are also a good choice for a house with 4 bedrooms and 1-2 bathrooms. However, we advise installing a new regular boiler only if you already have one installed. Here is our list of the best regular boilers for a 4-bed house. The prices shown are estimates.
Baxi 825 Heat
The Baxi 825 Heat is an efficient condensing regular gas boiler designed for wall-mounted installation.
Size (output rating). Its CH output of 25kW makes this unit suitable for properties with around 15 radiators.
Efficiency. It features a seasonal efficiency rating of 93% and an ErP A-rating for heat. As a highly efficient boiler, the Baxi 825 Heat has the potential to lower your energy bills.
Warranty/Guarantee. Baxi 825 Heat boilers come with a 10-year warranty.
Price. Its typical total price (including VAT, installation cost, and fittings) ranges from £1,685 to £2,185.
Ideal Logic Max Heat H24
The Logic Max Heat H24 is a highly reliable condensing wall-mounted regular boiler designed and manufactured by Ideal.
Size (output rating). Its 24.2kW CH output rating makes this a great boiler for homes with up to 15 radiators.
Efficiency. The Logic Max Heat H24 is a highly-efficient boiler. It boasts an efficiency rating of 94% and an ErP A-rating for heat.
Warranty/Guarantee. This boiler is available with a 10-year warranty as standard.
Price. You will most likely pay between £1,798 and £2,298 for this boiler, including VAT, installation cost, and fittings.
Vaillant ecoFIT Pure 425
The ecoFIT Pure 425, by Vaillant, is a condensing regular gas boiler that delivers highly efficient performance.
Size (output rating). The ecoFIT Pure 425 has a CH output rating of 25.4kW. It is well suited to properties with around 10 radiators.
Efficiency. It is a highly-efficient regular boiler with an efficiency of 94% and an ErP A-rating for heat. These figures mean that for every £1 spent on heating the home, only 6p is wasted.
Warranty/Guarantee. Its 2-year standard warranty can be extended to 7 or even 10 years when installed by a Vaillant Advance installer.
Price. Its typical total price ranges from £1,776 to £2,276, including VAT, installation cost, and fittings.
Are any of these combi, system or regular boilers a match for your home? We can help you find up to 3 quotes from Gas Safe, and OFTEC registered engineers near you. Once you receive the offers, you can compare them to find and lock in the best deal.
Comparing quotes is one of the best and easiest ways to lower costs and avoid being overcharged. Start saving on your new boiler by clicking on the button below. You are under no obligation to accept any of the quotes you receive.
What size system boiler do I need for a 4-bed house?
For a 4-bed house you need a boiler with a high output rating. The maximum CH output rating of a system boiler suitable for a 4-bed house typically ranges from 18kW to 26kW. Generally, the higher the output rating, the more radiators the boiler can run.
Can a regular boiler heat a 4-bed house?
Yes, a regular boiler can heat a 4-bed house. However, we recommend a system boiler, as regular boilers require additional components and extra pipework.
Can an electric boiler heat a 4-bed house?
Electric boilers are best suited to smaller homes and flats, as they tend to be less potent than gas and oil boilers. You need to find the right boiler size to heat a 4-bed house so that it’s capable of meeting your central heating and domestic hot water demands.
What size boiler for a 5-bed house?
For a 5-bed house, you will likely need a combi boiler with a CH output rating between 35kW and 42kW or a system or regular boiler with a CH output rating between 26kW and 40kW.
What size boiler for a 3-bed house?
A combi boiler with a CH output rating between 24kW and 27 kW would be powerful enough for a 3-bed house. A system or a regular boiler with an output rating between 9kW and 18kW will also do the job.
Luis Antonio Gómez Pérez is a seasoned Senior Content Writer with international reporting experience. He enriches Boiler Guide with his expertise in sustainability and energy efficiency, as well as with knowledgeable and reader-friendly articles.
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