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What is the Best Boiler for a Small House?
The best boiler for a small house is, without a doubt, a combi boiler. These boilers are compact units capable of running your radiators efficiently and delivering hot water for domestic purposes on demand.
In theory, system and conventional boilers could be suitable for a small house. Indeed, some of them have low output ratings, appropriate for homes with 1-2 bedrooms and 1 bathroom. However, as these types of boilers also require somewhat bulky external components, they are not recommended for properties where saving as much space as possible is a need.
This is why, in this article, we will focus on what is the best combi boiler for a small flat. If you are looking for the best boiler for a larger house, check our articles Best Boiler for a 3-Bed House, Best Boiler for a 4-Bedroom House and Best Boilers For Large Houses to find the one that best suits your home’s needs.
If you already have an idea which type of boiler you’d like and are simply looking for a reliable installer, we can help you with that too. Researching and contacting installers one by one on your own can be frustrating and take up hours of your free time. But it doesn’t have to be this way – GreenMatch can make the process of getting your ideal boiler easy for you.
We can quickly connect you with up to 3 qualified installers available in your area. You can then compare their quotes to ensure you’re getting the best value for your money. What’s more our service is completely free and non-binding. Click the button below to get started.
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Best Boiler for a Small House
As we have just mentioned, combi boilers are the most common and effective heating solution for small houses and flats. They are compact, powerful and also very efficient, which can help you save on your energy bills.
Combi boilers can run on natural gas, LPG (Liquefied Petroleum Gas), oil or electricity. The first one is the most common heating fuel across the UK, while the last three are more frequent in homes disconnected from the national gas grid.
In this regard, oil and LPG combi boilers require some space dedicated to storing the fuel they burn, which becomes a disadvantage if your home has a limited usable area. In other words, oil and LPG combi boilers may not be optimal for the type of property that concerns us in this article.
An electric combi boiler, on the other hand, is a great boiler for a small flat with no gas connection. Additionally, these compact boilers are easier to install than gas boilers and, therefore, can reduce the total boiler costs.
They can also help you reduce running costs and your home’s carbon footprint if you combine them with solar power or other renewable energy sources. For additional insights, check our article on gas boilers vs electric boilers.
How many kW boiler do I need for a small house?
How powerful a boiler should be for a small flat depends on factors such as the number of radiators, the size of the rooms, the height of the ceiling and how well-insulated the rooms are. However, there are some ways to estimate the appropriate boiler size (measured in kilowatts, kW) for a small house.
For gas combi boilers, you can approximate 2kW for each radiator in your home. For instance, a small house with 6 radiators will require a boiler with a central heating (CH) output of around 12kW.
While 18kW is the lowest maximum CH output rating you can find in the UK for a combi boiler, it does not mean that gas combi boilers are oversized for small flats. Actually, boilers work within an output range —e.g. 3.2kW (minimum) – 19kW (maximum).
Electric combi boilers, on the other hand, tend to be less powerful than their gas-fueled counterparts. The rule of thumb for electric boiler sizing suggests that you need 1.5 kW for each radiator in your home.
You can check the table below to get an idea of how many kW a boiler should be for a small house.
| Approximate Combi Boiler Sizes | ||
|---|---|---|
House Size | Gas Combi Boilers (CH Output) | Electric Combi Boilers (Output Rating) |
Studio (2-3 radiators) | 18kW (lowest CH output available) | 3kW – 4.5kW |
1-bedroom home (up to 4 radiators) | 18kW (lowest CH output available) | 6kW |
2–bedroom home (up to 6 radiators) | 18kW (lowest CH output available) | 9kW |
Is my boiler too small for my house?
A boiler is too small for a house if it struggles to run your radiators, achieve the ideal temperature in the room or if it does not supply enough hot water to your taps and shower. Fortunately, combi series by most manufacturers operating in the UK start at output sizes that can cope with the demand of small flats.
For homeowners with small homes, the problem would be getting a boiler with an excessively high output rating. In this case, you will pay a higher upfront price, as more powerful boilers are usually more expensive.
Furthermore, if you install an electric combi boiler that is too big, you may use more energy than you need. Therefore you’ll unnecessarily pay a lot of money on energy bills, especially considering the high prices of electricity across the UK.
If you have a larger home with more than one bathroom, then we recommend you also consider a system or regular boiler.
However, the best way to determine what type of boiler and what boiler size best suits your home is to get expert advice from a professional installer. Nevertheless, you must be prepared to spend a lot of time researching if you want to find the right heating engineer yourself. Fortunately, we can help you with this. Find an overview below:
- Spend several hours online searching for local heating companies
- Research each of the companies you find to ensure they are trustworthy
- Gather information and contact details from several installers
- Email or call them on the phone, one by one
- Collect enough quotes, and compare the offers you receive
- Spend less than 1 minute filling in 1 form
- Receive up to 3 FREE quotes from trusted heating engineers in your area
- Compare and pick the offer that best meets your needs (no need to accept any offer you receive)
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Best Combi Boiler for a Small House
If you wonder what the best combi boiler of 2024 for a small flat is, check our list below. In this section, we’ve included the best gas boilers for small houses. We considered high-quality units by the most reputable boiler manufacturers in the UK. These are our picks:
1. Ideal Vogue Max C26
- Max. CH output: 18kW
- Max. DHW output: 26kW
- Suitable for: Homes with around 10 radiators
- Efficiency: 93% efficiency and ErP A-rated for heat and hot water
- Warranty: 10-year warranty, increased to 12 years if installed and serviced by a Max accredited installer
- Estimated price (Exc. installation): £1,089
2. Viessmann Vitodens 100-W 19kW
- Max. CH output: 19kW
- Max. DHW output: 27.3kW
- Suitable for: Homes with 1 bathroom and up to 10 radiators
- Efficiency: 94% efficiency and ErP A-rated for heat and hot water
- Warranty: 5-year guarantee with the option to extend by a further 7 years
- Estimated price (Exc. installation): £1,125
3. Vaillant ecoFIT pure 825
- Max. CH output: 19.1kW
- Max. DHW output: 25.2kW
- Suitable for: Smaller homes with 10-15 radiators and 1 bathroom
- Efficiency: 94% efficiency and ErP A-rated for heat and hot water
- Warranty: 2-year guarantee as standard, with 7 to 10 years available when you book a Vaillant Advance installer
- Estimated price (Exc. installation): £907
4. Worcester Bosch Greenstar 2000 25kW combi
- Max. CH output: 20kW
- Max. DHW output: 25kW
- Suitable for: Properties with fewer than 10 radiators and a single bathroom
- Efficiency: 93% efficiency and ErP A-rated for heat and hot water
- Warranty: Up to a 6-year guarantee
- Estimated price (Exc. installation): £730
Best Electric Combi Boiler for Small Flat
In this section, we have put together our candidates for the best electric combi boiler for a small flat. The three of them are simple to install and incredibly efficient.
It is worth pointing out that electric boilers do not release CO2 into the atmosphere. This makes them a greener alternative, as long as the electricity powering them is generated from renewable sources.
However, you must be aware that if you are not able to generate your own electricity (e.g. using solar panels in the UK), you will spend much more money running an electric combi boiler than a gas combi boiler. Currently, electricity is 4 times more expensive than gas in the UK. Nevertheless, an electric boiler for a small flat is still worth considering.
1. ELNUR Mattira MAC15
- Max. Heating Power: It can modulate from 3kW to 15kW
- Suitable for: Small homes with 2 radiators to medium-sized homes with around 10 radiators
- Efficiency: This boiler’s efficiency varies depending on the power output it is operating. At 3kW, it is 100% efficient. However, at 15kW, efficiency decreases to 36,4%. The Mattira MAS15 has an ErP D-rating
- Warranty: Internal components are warranted against faulty materials and manufacture defects for 2 to 5 years from the date of purchase
- Estimated price (Exc. installation): £2,370
2. Electric Heating Company Comet Combi Boiler 9kW
- Max. Heating Power: 9kW
- Suitable for: Homes with 6 radiators and a single bathroom
- Efficiency: 100% efficiency and ErP D-rated
- Warranty: 5-year guarantee
- Estimated price (Exc. installation): £2,400
3. Electric Heating Company Mercury Combi Boiler 12kW
- Max. Heating Power: 12kW
- Suitable for: Small properties with 1 bathroom
- Efficiency: 100% efficiency and ErP D-rated
- Warranty: 5-year guarantee
- Estimated price (Exc. installation): £1,394
While the best electric boilers boast 99-100% efficiency ratings, many of them have an ErP (Energy-related Products) D-rating. This is rather low compared to the A-rating awarded to gas boilers. The reason is that most electricity is generated by burning fossil fuels. Therefore, it is considered carbon-intensive and not very efficient.
However, renewable energy generation has increased considerably in recent years. Hence, the ErP rating given to electric boilers will likely improve in the near future.
At GreenMatch, we are committed to helping you navigate the transition to more sustainable ways of heating your home. In this regard, switching to low-carbon systems may be the greenest choice. However, we know that these are expensive alternatives.
If you are not ready yet to switch but still want to make a difference for the environment, consider installing a highly-efficient gas combi boiler or an electric combi boiler, ensuring that it runs (mostly) on renewable-generated electricity.
The positive environmental impact of the latter is evident, but you can also help the planet by upgrading your gas boiler. Replacing a 70% efficient old gas boiler with a 90% efficient condensing boiler will allow you to achieve the same heating result with around 20% less fuel. If you burn less fuel, you will also reduce your CO2 emissions.
How much CO2 emissions you can save depends on your property size and its demand for heating. For an average household of 2-3 people, it would be approximately 483kg of CO2 equivalent less per year.
According to data displayed by The Guardian’s interactive flights CO2 calculator, that amount is comparable to the total CO2 generated by flying from London to Antalya (Turkey) and back.
You can make a difference by upgrading your boiler today! But how do you find the right boiler and someone who is reliable to install it? Trying to do this on your own can be confusing and waste hours of your free time – so let our team at GreenMatch help you.
At GreenMatch, we have a wide network of qualified boiler installers across the UK. We can connect you with up to 3 installers available in your area whose quotes you can then compare to select the best price. Our service is free and non-binding, so you’ve got nothing to lose! Click the button below to get your free quotes now and have your new boiler installed in your home as soon as possible.
- Quotes from local engineers
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FAQ
Luis Antonio is a seasoned Content Writer with international journalism experience. His writing style, enriched by a Master’s in Journalism, contributes informative content to GreenMatch on topics including low-carbon heating systems.
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