The Best 10 System Boilers From £559 (2026)
A new gas system boiler costs about £900–£2,200 inc. VAT to buy, boiler only; fitted with installation, expect around £3,000–£3,500.
Introduction
Are you looking for the top 10 system boilers for your home?
Did you know that system boilers don’t need a cold water tank, which means you can benefit from being able to free up some of your space?
Or that many system boilers are highly energy efficient and can help you save significantly on your annual bills?
Yes, really.
In this guide, you’ll find out about the top 10 system boilers available right now, where you can buy them, and the costs you can expect.
Ready? Let’s get going!
The Top 10 System Boilers
1. Vokera Vision 20S System Boiler
Type: System boiler
Price: £758 (including VAT)
Supplier: Mr Central Heating
Warranty: 7 years
This system boiler would be an excellent fit for a small to medium-sized home, which can benefit from both central heating and hot water.
Like most system boilers, you will require a hot water cylinder which will store all of your hot water.
The Vokera Vision 20S System Boiler comes with a 7-year warranty, compact design, low price, and speedy delivery.
2. Glow-worm Energy7 25S System Boiler
Type: System boiler
Price: £1,206.54 (including VAT)
Supplier: Mr Central Heating
Warranty: 7 years
Glow-worm offers a range of boilers, including this system boiler which is fully ErP compliant and complies to all policies that aim to reduce carbon footprints for residential homes.
This boiler has an output of approximately 25kW, which can easily power a two- to three-bedroom house with one bathroom. You will need a hot water cylinder to store your water.
This boiler comes with a 5-year warranty, and they claim it is ultra quiet as well.
3. Vaillant ecoTEC Plus 612 (ErP) System Boiler
Type: System boiler
Price: £1,142.21 (including VAT)
Supplier: Mr Central Heating
Warranty: 5 years
Vaillant ecoTEC Plus 612 (ErP) System Boiler gives you 12kW of power, which makes it the most suitable option for a one- or two-bedroom flat, with a compact design and premium quality materials.
System boilers such as this model takes the water it heats up directly from the mains so that you won’t need a cold water tank.
This boiler can be powered with natural gas. Moreover, it is ErP compliant, and has a modern design and maximum energy efficiency.
4. Worcester Greenstar 4000 21 (ErP) System Boiler
Type: System boiler
Price: £1,463.58 (including VAT)
Supplier: Mr Central Heating
Warranty: 7 years
From Worcester-Bosch, this system boiler has a 21kW power output, which is enough to be able to heat a two-bedroom home with one bathroom comfortably.
With a compact and modern design, they claim that this boiler could help you reduce your annual heating bills by 15% to 20%.
They also claim that you won’t need to be worried about needing to replace your boiler for a long time, as they are made with high-quality materials and they will last longer with regular servicing.
5. Baxi Megaflo 24 System Boiler
Type: System boiler
Price: £1,010.35 (including VAT)
Supplier: Mr Central Heating
Warranty: 7 years
The Baxi Megaflo 24 System Boiler is one of the most compact designed system boilers that Baxi has created, and will give you 24kW of energy output which can power a two- to three-bedroom house.
These types of boilers are ErP compliant. In addition, they have an A-rated energy efficiency rating and could save you upwards of £300 annually on your energy bills.
Some of the advantages of choosing Baxi include easy installation, access for servicing, and free delivery.
6. Ideal Vogue S32 Gen2 System Boiler
Type: System boiler
Price: £1,637.88 (including VAT)
Supplier: Mr Central Heating
Warranty: 8 years
The Ideal Vogue S32 Gen2 System Boiler is one of the most expensive but highly efficient system boilers on the market, which is made from premium components and manufactured in the UK.
This boiler will provide you with 32kW of energy output, which can efficiently heat a three- or four-bedroom house with up to two bathrooms.
Some of its benefits include an 8-year warranty, frost protection, and an LCD colour display.
7. Ferroli Bluehelix 24
Type: System boiler
Price: £559 (including VAT)
Supplier: WRPM
Warranty: 10 years
The Ferroli Bluehelix 24 is one of the most cost-effective models for smaller homes, with a power output capacity of 24kW, which is a suitable choice for a two- to three-bedroom flat.
These boilers have many advantages, including low-noise, compact and light size, and high energy performance.
Ferroli claims that this range of boilers are highly reliable. Plus, you can benefit from a generous 10-year warranty.
8. Keston 30 System Boiler
Type: System boiler
Price: £1,365.00 (including VAT)
Supplier: Hawk Heating Supplies
Warranty: 7 years
The Keston 30 System Boiler is a reliable and affordable option with a powerful 30kW output, which can comfortably heat a three-bedroom home with up to two bathrooms.
As with all system boilers, this one will require a hot water cylinder to store your hot water. However, your boiler can be installed in a kitchen cupboard.
Some of its main features are that it is light, compact, and highly efficient. In addition, there is a digital display, and the boilers are British-built.
9. Main Elite Eco 24kW System Boiler
Type: System boiler
Price: £1,070.40 (including VAT)
Supplier: BoilerNBits
Warranty: 5 years
The Main Elite Eco System Boiler comes with a 24kW output, which can power a two- or three-bedroom home with one bathroom. It also comes with a 5-year warranty.
This type of boiler has many advantages, including a user-friendly interface and high energy efficiency. Plus, it is endorsed by the Energy Savings Trust and has low emissions.
These boilers are made from top-quality materials and manufactured in the UK.
10. Potterton Assure 24 (ErP) LPG System Boiler
Type: System boiler
Price: £1000.49 (including VAT)
Supplier: Mep Stock
Warranty: 2 years
The Potterton Assure 24 (ErP) LPG System Boiler gives you 24kW of power output, which can power a two-bedroom home, but still with a sleek design which can be installed in a cupboard.
Some of the features include frost protection, ErP-compliant, parts and labour warranties, and low emissions.
This boiler uses a smart system that enables it to calculate the right amount of fuel needed to save on energy bills.
FAQ
What is a system boiler?
A system boiler is one of the most popular types of the boiler on the market today and works by taking water from your mains, heating it up, and then storing it in a hot water cylinder.
Then, you can use the stored hot water for your showers, baths, or taps and radiators.
This feature allows you to free up space in your loft which would have otherwise required a cold water tank. However, it does come with some disadvantages, such as when your hot water is gone, you have to wait for more to be heated and stored again.
What are the benefits of having a system boiler?
These are the advantages of having a system boiler for your home:
- ✔ Easy installation.
- ✔ An excellent choice if you have a high demand for hot water.
- ✔ Allows you to use hot water in several places simultaneously.
- ✔ Gives you high water pressure, which is perfect for showers.
- ✔ Low cost to run and an affordable initial price.
- ✔ You don’t need a cold water tank to store water.
What are the disadvantages of choosing a system boiler?
Although there are benefits to choosing a system boiler, there are some disadvantages as well, such as:
✗ You will need a hot water cylinder to store water.
✗ Once you run out of hot water, you need to wait for more to heat up.
✗ Your boiler needs to be adequately insulated.
✗ The amount of hot water you have depends on the size of your cylinder.
Where can I find system boilers?
When you are looking for a system boiler, there are many options available in terms suppliers and brands.
There are many potential advantages to consider, such as free delivery and extended warranty options.
Here are some places you can find excellent system boilers.
- Screwfix
- City Plumbing Supplies
- PlumbNation
- Mr Central Heating
- Travis Perkins
- Wolseley
What is the best system boiler?
The best system boiler for your home might depend on these factors:
- The size of your home
- Your budget
- The cost of running your boiler
- Your required power output
- How many people live in your home
- Whether you need hot water instantly
- The space you have for a hot water cylinder
How much do system boilers cost?
Because of the full range of system boilers on offer today, you have many options that match your specific budget.
For instance, on the lower end, a boiler suitable for a one-bedroom flat might only cost around £500. Meanwhile, a boiler with an output of over 30kW, which is an excellent fit for a three- or four-bedroom home, might cost £1,000.
Are system boilers more expensive than combination boilers?
On average, a system boiler could cost the same amount as a combination boiler.
This is why you should always compare quotes for your boiler, as there is a vast selection to choose from, depending on the features you’re looking for.
Conclusion
System boilers provide both centralized heating and hot water storage. As such, they’re more compact and lightweight than conventional boilers because they don’t need a cold water tank.
Do you want to discover more about boilers?
To answer more of your potential questions, check out the Ecopreneurist guides here.
Or you can fill out the form at the top of the page for a bespoke quote, tailored to your needs and budget.
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