System boilers are quite common and popular in the UK. They are good for large homes because they can supply hot water to more than one bathroom and taps. If you want to buy a system boiler, then you might find yourself asking: what is the best system boiler?

On this blog, we will be looking at the best brands of system boilers in terms of their efficiency, reliability and overall performance. Other factors that may influence the price of your system boiler will also be discussed such as the kW output, warranty and installation cost.

What is a system boiler?

A system boiler consists of a separate cylinder that is used to store hot water. Most of the major heating parts are built into the boiler. However, the hot water is stored in the cylinder in order to provide a constant hot water supply for your taps and showers. That is why it is ideal for large homes that have a high hot water and heating demand.

How do system boilers work?

A system boiler gets its cold water supply directly from the mains. After that the heat exchanger within the boiler would heat up the water. This hot water is then kept in the hot water cylinder ready to be used on demand. The electric pump is used to push the hot water through to your taps and radiators. System boilers use condensing technology. That is why they are energy efficient. 

What Are the Advantages of System Boilers?

A large supply of hot water

Generally, with a system boiler you can store large quantities of hot water to use later on. This is very useful when you are using multiple taps, showers and radiators at the same time.

The ability to use solar energy.

Without a doubt, connecting the correct cylinder to the system will enable you to use solar panels. This is not only environmentally friendly but it is also cost-effective and will save you some money.

Needs less space than a regular boiler

Of course, system boilers are easier to install and need less space than regular boilers. Moreover, they do not need an expansion tank or external expansion vessels.

Economical and fast

Lastly, system boilers consist of a pump. As a result, they respond fast and have more economic running costs.

Important things to consider in System Boilers

There are also some drawbacks to installing a system boiler that you should keep in mind. Here are a few of them:

System boilers need more space than combi boilers

Although they take less space than regular boilers, they still require more space than combi boilers because of the external cylinder. Overall, this can be a huge problem in smaller homes when it comes to installations.

Busier times means more patience

Firstly, your cylinder will be sized in advance to cover your household need of water (usually 50 litres of hot water stored per person). However, in times when you have more visitors than usual and your use of hot water is doubled, your hot water storage may run dry. As a result, you will have to wait 30-40 minutes while your boiler is reheating the cylinder again.

Read about: Top UK System Boilers

What is the best system boiler brand?

1. Worcester Bosch

Worcester Bosch is a United Kingdom based heating and hot water products manufacturer. The company was established in 1962 by Cecil Duckworth as Worcester Engineering Co Ltd in Worcester, England.

Worcester Bosch is the UK market leader in domestic boilers. They have earned recognition and high acclaim over the last 50 years. Moreover, they have won multiple awards.

Worcester Bosch range of system boilers:

• Greenstar 8000
• Greenstar 8000 Style
• Greenstar 8000 Life  
• Greenstar i       
• Greenstar Danesmoor (oil boiler)       
• Greenstar Danesmoor External (oil boiler) 
• Greenstar Danesmoor Utility (oil boiler)      
• Greenstar Condens 7000 WP (oil boiler)

What is the output range on Worcester Bosch system boilers?

System boilers are ideal for medium sized homes with a high demand for hot water and heating. A system boiler operates alongside a hot water storage cylinder in order to ensure that enough hot water is available when needed.

• The Greenstar 4000 system boiler has an output of 12 – 24kW and can support up to 12 radiators.
• The Greenstar 8000 system boiler has an output of 30kW and can support up to 15 radiators.

The Greenstar 4000 System boiler

The price for the Greenstar 4000 ranges between £975 – £1,200. As for the installation cost it is between £500 to £1,000, depending on different factors.

This is one of the best and most powerful Worcester Bosch boilers. It has also won the Which? Best Buy award in 2022. With this model you will get a number of benefits.

The Greenstar 4000 is available as both a system and a combi boiler. It is suitable for most types of homes.

Read more: The Best Brands of System Boilers & Pricing

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What are the key features of the Worcester Bosch Greenstar 4000?

• This model is very quiet
• Has a 10 year guarantee (given that it is installed by accredited worcester installer
• Has an A-rated efficiency on the ErP scale. This feature can save you money on energy bills because your boiler will waste very little energy
• Compact and easily installed
• 20% Hydrogen ready
• It can be connected to Greenskies solar panels
• When combined with a hot water storage cylinder, your system will be able to provide for multiple bathrooms
• This system can be used with wireless smart control using Bosch EasyControl

The Greenstar 4000 boiler offers a range of output options so that you can choose the one that best fits your home. By choosing the right level of power, you will be able to save money due to reduced heating bills.

• Viessmann

Whether we are talking about domestic or commercial heating solutions, Viessmann Boilers are known for their high quality and outstanding performance. They produce a range of products that include boilers, hot water cylinders, heat pumps, photovoltaics and solar thermal systems.

To bring down the cost of energy and to reduce your heating bills, Viessmann produces boilers that are highly efficient. By using the latest technologies Viessmann aims to provide innovative heating solutions.

Vitodens 200-W B2HE System boiler

For medium homes with high energy demand this can be a great option. The Vitodens 200-W B2HE System can support 1 bathroom and up to 15 radiators. It has a central heating output of up to 32kW and a domestic hot water output of up to 29 kW. It goes without saying that this is the most powerful system boiler made by Viessmann. The cost for the Vitodens 200-W B2HE System can be between £1,344 – £1,650 without the cost of installation.

What are the key features of the Vitodens 200-W B2HE System boiler?

• Warranty of 5 years, and can be extended up to 12 years
• Central heating output available in 11, 19, 25, 32 (kW)
• Energy efficiency: A-rated
• By using ViCare thermostat it can be Wifi-enabled
• Can achieve better efficiency with Inox Radial heat exchanger
• Internal combustion control using Lambda Pro Plus
• Less pollutants with MatriX plus burner

Viessmann system boilers output range

Viessmann system boilers have an output range of 11kW to 32kW. This range can be suitable for small and medium sized homes as well.

• The Vitodens 200-W B2HE has central heating power output of 11 kW and can support homes with 1 bathroom and 5-10     radiators.
• The Vitodens 100-W B1HC has a central heating power output of 32 kW and can support homes with 1 bathroom and 10-15 radiators.

• Vaillant

Vaillant has more than 140 years of boiler and central heating experience. They helped and paved the way for the introduction of the combi boiler. Vaillant has been working on more environmentally friendly solutions. They have a wide range of air source heat pumps.

Vaillant is the second largest boiler manufacturer in Europe and they operate in more than 20 countries.

Vaillant boiler range

Vaillant has 2 main boiler models to represent their boiler range:

• The Vaillant ecoTEC
• The Vaillant ecoFIT

These two models are available in combi, system and regular boiler types. You can also get the ecoTEC as a storage combi boiler with an integrated hot water tank.

Whether you are looking for a combi, system or regular boiler, Vaillant has a popular model for each type.

The ecoTEC plus also takes the first spot for their most selling system boiler. This type is available in different outputs so that you can choose which model suits your home the best. It has the ability to reduce your energy consumption due to its built-in advanced modulation that can save you money on energy bills.

How much do Vaillant system boilers cost?

Vaillant system boilers have a price tag that ranges between £900 to £2,700, depending on the size and the output. The higher the output, the more money your boiler will cost.

Read more: New Boiler Cost

What is the output range on Vaillant system boilers?

The output range for Vaillant system boilers is between 12kW to 64kW. That is why they are suitable for properties which have between 6 and 42 radiators.

System boilers are excellent when it comes to providing large amounts of hot water or heating to your home. They do not require a feed tank in the loft which makes them very practical. What is more, they are an excellent option for replacing a combi boiler that is unable to meet your demand for hot water and heating.

• Ideal

Ideal Heating manufactures high-quality boilers for domestic use. They have a wide range of boilers that includes combi, system and regular boilers. If you are interested in Ideal boilers, then you have come to the right place.

Ideal offers various options to suit your heating needs. You will be able to choose from boilers with different efficiency ratings, outputs, fuel types, warranties and prices. Whether you live in a small or a large home, Ideal has the perfect heating solution.

Ideal System Boilers

• Logic Max System
• Logic+
• Vogue Max System
• Vogue Gen2

Ideal Logic system gas boilers

This range of Ideal system boilers is lightweight and compact in design so there will be no need for compartment ventilation. As a result, it can be fit into small places like your kitchen cupboard. This Ideal Logic System boiler is endorsed by the Energy Saving Trust. An additional feature of this range is the PRV wall outlet pipe that would help with installation.

The Logic system models are A-rated and have central heating outputs of 15kW, 18kW, 24kW, and 30kW. So it is best suited for medium sized homes with 10 to 20 radiators. The price for the Logic system is between £785 – £920 (without installation).

Read about: Best combi boilers & boiler brands

What are the key features of the Ideal Logic system gas boiler?

• Standard 2 years warranty
• Uses gas as fuel; compatible with 20% hydrogen blend
• A-rated energy efficiency
• Easy-to-see pressure gauge
• Full backlit display
• Boiler frost protection
• Fully modulating temperature

Ideal system boilers output range

System boilers that are produced by Ideal have different outputs, ranging from 15kW to 32kW. As a result, this range of regular boilers is suitable for homes with 10 to 17 radiators. Ideal system boilers are also perfect for homes with multiple bathrooms and high hot water demand thanks to their hot water cylinder that stores hot water for later use.

• Baxi

Baxi has been in the boiler business since 1866. Their customer service is award winning and they are one of the leading manufacturers of heating solutions in the UK. Baxi boilers are a popular option for many homes in the UK.

Baxi produces different types of boilers (combi, system and regular) that come in a wide range of outputs to suit your home. Baxi boilers are also known for being easy to maintain and install. Their range of light lift weight models allow easier installation. Moreover, Baxi boilers are recognised for being affordable when it comes to their cost.

Baxi system boiler models

• Baxi 600 System
• Baxi 800 System
• Baxi Megaflo System

Baxi Megaflo System Boiler

This range of baxi boilers is suitable for homes with multiple bathrooms and high hot water demand. To achieve powerful water pressure they can be installed alongside an innovative Megaflo Eco cylinder. And since they are compatible with multiple flue types, they offer a range of installation options.

Baxi system boiler output range

Baxi’s range of system boilers have an output of 12kW to 32kW. They are suitable for most types of homes. Nonetheless, they do require some space for the hot water storage cylinder. System boilers are ideal for large homes since they have a hot water storage that can supply multiple outlets.

• The Baxi Assure System 12 model has a power output of 12.9kW that can heat homes with 1 bathroom and 6-12 radiators.

• The Baxi Platinum+ 32kW System model has a power output of 32kW that can heat homes with 2 bathrooms and 15-20 radiators.

Read more: Different Types Of Reliable Boiler Systems Explained and their Costs

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Why choose smartadapt?

We’re Punctual

We always aim for simplicity and quality of work. Using the latest and the beat management system to schedule jobs and confirm appointments, send reminders and issue certificates and send bills. We offer next-day installations and emergency services as well. We’re very quick to respond to your call and will be at your doorstep in no time.

We Care

Establishing a good relationship with our customers is our priority. We always take the time to understand what your heating requirements are. We do our best so as not to create any sort of disruption to your home or make so much noise.

Experienced Staff

Our experience in the heating business has paved the way for us to expand further and provide our services nationwide. We’re very committed to our work. Our engineers are helpful and informative. They are highly skilled and have a wide knowledge of their trade. Our services include: boiler installation, maintenance, repair and boiler service plan. We work with all types of boilers: heat only boilers, system boilers and combi boilers. We install heat pumps and central heating systems. And we also provide plumbing services and much more.

Read about: Best Condensing Boilers

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