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Updated: May 2, 2024

What are the Different Types Of Boiler Systems?

There are four main types of boiler systems or heating systems, that you can install into your home: combi boilers, heat only (regular boilers), system boilers and Heat pumps.

The four main types of boiler systems or heating systems that we recommend and install at Let’s Heat are:

  1. The Common, Heat Only Boiler
  2. A System Boiler
  3. Combi Boilers / Condensing Boilers
  4. NEW Heat Pumps!

Here you will find lots of information on the different types of boilers and heating systems* available to you. This is for both heating your property and heating your hot water.

There are also three different types of boiler installations to consider:

  1. Straight Swap
  2. Boiler Relocation
  3. System Upgrade

We have compiled a list of the top boilers, boiler brands and boiler pricing for each of the different types for you!

*Please also see our additional article on the different types of boiler installation below this article.

Bathroom Installation In Cardiff

Different Types of Boiler Systems Explained – The Heat Only Boilers, Brands & Prices… domestic boiler systems

Heat Only or common boilers cost from approx £500 to £2000 dependent on the brand and the size of the model etc.

Heat only boilers or common boilers, are a traditional domestic boiler type, which were often found in all homes in the UK that were  built before 1970.

Where located?

The heat only boiler directly provide heating and hot water from a storage cylinder, usually situated in the airing cupboard.

The boiler is fed by a cold water cistern from above (usually the attic), via gravity.

Needs plenty of space:

The expansion cistern is separate so this boiler system requires a reasonable amount of space.


The Heat only boilers vary greatly in price because of the wide variety of brand and models  that are available, with some models starting at £500, and me reaching up to £2000.

Heat Only Boiler Brands & Prices…


  • GREENSTAR UTILITY 50 – 70 (OIL) – Typical Price – £1,700 – £1,900
  • WORCESTER BOSCH GREENSTAR FS 42CDI REGULAR – Typical Price – £1,500-£1700
  • WB GREENSTAR 30CDI REGULAR – Typical Price -£1,200-£1,300


  • VAILLANT ECOTEC PLUS 428 – Typical Price – £800 – £900
  • ECOTEC PLUS 415 – Typical Price – £600-£800

Heat Only Boilers Prices and Sizes

The cost of your Heat only boiler would depend on the size of your house and the fuel type required etc. 

Great for larger properties:

Heat-only boilers are ideal for larger properties as they have a high flow rate, are able to meet high hot water demands.  This means they can have multiple taps or showers on at any one time.

They will however require more space than other boilers such as the combi, and the use of hot water is limited by the size of your cylinder so once it’s gone, you must wait for it to reheat.

Boiler brands and prices for different sized properties:

Heat-only boilers for smaller properties

If you live in a small property and space is of primary concern, there are more compact, wall mounted options for your heat-only boilers.



Output – 12;15;18;24;32KW

Price: £500-£600

Brand: BAXI SOLO 12 HE

Output – 12;15;18;24;30;35KW

Price: £600-£700

Heat-only boilers for medium to large Properties

Medium and large sized properties need a heat only boiler, with a high output; ensuring that you are able to heat your entire home.


Output – 38KW

Price: £1,200-£1400


Output – 30;42KW

Price: £1,500-£1700

Read about: Electric Boilers v Gas Boilers

Different Type of Boiler Systems Explained – Best combi boilers & brands…

UK Combi boiler brands and reviews:

According to UK consumer brand Which, “if you want to buy the best combi boiler, you will  need to make sure it’s the correct size for your home and from a reliable brand.”

The Which? article then went on to rate the Most common brands of Combi boiler under the following categories:

  • Overall score,
  • Reliability score,
  • Customer score,
  • Engineer overall score,
  • Typical price for a 30kW Combi boiler.

For all score please see the full which article by clicking the link!

The Typical prices for the UK combi boiler brands were listed in the article as;

  • Baxi £880 – £1,000
  • Glow Worm £700 – £990
  • Ideal £590 – £1,270
  • Potterton £650 – £1,350
  • Vaillant £1,160 – £1,410
  • Viessmann £780 – £1,280
  • Worcester Bosch £800 – £2,460

When this was done!

The Which? article says that the Reliability and brand customer score was based on responses from 8,001 members of the public who’ve bought a combi boiler in the last six years, that took place in May-June 2021.

Brand Engineer Score

The Brand Engineer Score was derived from feedback collected from 153 Which Trusted Trader heating engineers in June 2021. The typical price range considered in the assessment reflects the low and high price brackets for a standard 30kW combi boiler across the brand’s entire range.

A 30kW boiler is well-suited for most medium-sized homes. It’s important to note that the prices mentioned for combi boilers do not cover installation costs, but our quotes will include them!

For further insights into the combi boiler assessment conducted by the consumer magazine Which?, visit their website.

Read more: What is a combi boiler and How They Work?

It is good to also consider what makes a good combi boiler?

As per the article, a reliable combination boiler ensures ample hot water for showers, baths, and sinks, while also maintaining consistently warm radiators even during the coldest winter months.

Additionally, the article discusses the brands identified by Trusted Trader Heating Engineers as the most reliable manufacturers of combination boilers.

What are the main UK brands that make these combination boilers?

As per the same Which? article which sites a 2021 boiler survey of 8,001 members of the public.

There are 17 gas and oil boiler brands that are all producing combi boilers. 

Please find some details and pricing for the top 7 combi boiler brands:

Brand: Baxi Boilers

Baxi stands as one of the largest manufacturers of combi boilers in the UK. Their range includes Assure, Duo-tec, Megaflow, and Platinum models, catering to various home sizes and types.

Price: Typically priced between £880 – £1,000 for a 30kW medium-sized combi boiler, with models available from around £550.

Brand: Glow-worm

Glow-worm offers several combi boiler ranges, including Energy, Essential, Betacom, Easicom, and Ultimate models.

Price: Prices start from around £560, with medium-sized combi boilers usually ranging between £700 – £990.

Brand: Ideal Boilers

Ideal, formerly known as the National Radiator Company, has been in operation for a century. They offer a range of combi boilers including Exclusive, Instinct, Esprit Eco, and Logic+ models.

Prices: A 30kW medium-sized Combi boiler starts from around £590, going up to £1,270.

Brand: Potterton Boilers

Potterton, part of the Baxi group, offers ranges like the Assure series. The Titanium Combi boiler brand is also under their ownership.

Price: Prices for the Titanium start at £800 for the 28kW size.

Brand: Vaillant Boilers

German manufacturer Vaillant produces the ecoFIT and ecoTEC range of combi boilers.

Price: These Combi boilers typically start between £1,160 – £1,410 for a medium-sized boiler of 30kW.

Brand: Viessmann Boilers

Viessmann, a German brand, offers the Vitodens combi boiler lines which were updated in 2021.

Price: Viessmann boilers cost between £780 – £1,280 for a mid-sized 30kW boiler, available in various sizes to suit different home requirements.

Brand: Worcester Bosch Boilers

German manufacturer Worcester Bosch is one of the largest combi boiler manufacturers in the UK.

Price: The Greenstar combi boiler range starts at around £800 and goes up to around £2,500, depending on the size and the hot water flow needed for your home.

Read about: best boilers in uk

Other things to consider?

  • Combi boilers are less suitable for homes with multiple bathrooms.
  • A faulty combi boiler will fail early and is likely to result in regular costly repairs.
  • On average, it costs almost £200 for a boiler repair so this can soon add up, making any cheaper boiler purchase more expensive than a more expensive but more reliable boiler, in the long run.(Which? survey, 2021).
  • It pays to invest in a boiler that will last. 
  • Size matters.  An oversized combi boiler will lead to you spending more on your heating and hot water than you need to, and an undersized one will deliver a disappointing flow of hot water to your taps and radiators.

Please read our guide on the  different types of boiler <<link>> to see which type will best suit your property and your requirements.

So, What makes a good combi boiler?

  1. In order to get the best combi boiler, it is crucial to choose a reliable brand that won’t break down.
  2. It’s also important to pick a combi boiler that’s the right size and fit for your home. 
  3. And you need to select the right boiler for your budget*

*we can assist you with finance should this be required for your new boiler purchase and installation.

How to pick the right size combi boiler for you property?

  • The simplest way to estimate the size of boiler you might need is to count the number of radiators you have.
  • If you have Fewer than 10 radiators you require a boiler under 27kW
  • For 10-15 radiators you need a boiler between 28kW and 34kW
  • Where there are more than 15 radiators you need a boiler with over 34kW
Emergency Boiler Repair

Different Types of Boiler Systems Explained – Best System Boilers, Brands & Pricing

System boilers are common in the UK.

System boilers are particularly favored among households with more than four occupants or properties featuring multiple bathrooms. Here’s some information, guidance, and pricing on the top system boilers to aid in your selection process. If you’re uncertain about whether a system boiler, combi boiler, or heat only boiler is the right fit for your needs, feel free to consult our convenient online guide for quick assistance!

Best System Boilers for this year, 2022 and beyond!

Please also take a look at our best combi boilers and best heat only boiler pages!

According to a recent Which? Article, the best 3 UK system boilers for 2021 and beyond are:

  • Viessmann Vitodens 100-W System
  • Worcester Bosch Greenstar i System
  • Vaillant ecoTEC Plus System

Brand: Viessmann

Model: Viessmann Vitodens 100-W Gas System Boiler

Details: The Viessmann Vitodens 100-W System boiler is a reliable and fantastic wall mounted gas condensing boiler. 

These gas system boilers are available for prices around £1000, making it a great choice for any home who wants a top-quality but affordable system boiler.

Boiler Sizes:

The Viessman Vitodens 100-W comes in 26kW, 30kW, and 35kW system boiler sizes.

This boiler is perfect for larger homes with more than four people, or more than one bathroom, where the demand for hot water is high and to multiple taps at once.

Energy Efficiency:

This system boiler rates ‘A’ Class in the SEDBUK energy efficiency ratings.

Main Features:

  • High modulation ratio of 1:6
  • SEDBUK A Rating
  • MatriX pre-mix cylinder burner and an integral AquaBloc hydraulic unit
  • Various Kw Heating Output -26kW, 30kW, and 35kW
  • Very Quiet Boiler
  • Optional external weather detector
  • Advanced technology
  • Which Rating 76%
  • LCD touchscreen
  • Compact size
  • Lightweight
  • 5- year parts and labour warranty as standard (Up to 10 years with Viessmann Installer)

Why first spot!

These were given 1st place due to high scores in areas like; quality, performance, lengthy warranty and value for money. 

Viessman Boiler Price:

This boiler is usually priced around £1,000 and with installation, you can expect a cost between £1800-£2200 depending on the installation cost of the company who’s installing it. 

Want a quote?

With us here at Let’s Heat you can get an online quote now to see how much we can install it for: Get Quote Now!

And please remember that whoever you use to install your boiler, please ensure that they are gas safe registered, as we are and that they have a great review score for their workmanship see our 4.9 Trustpilot rating here!

Brand: Worcester-Bosch

Model: Worcester-Bosch Greenstar 24i System Boiler Reviews

Details: The Worcester-Bosch Greenstar 24i System Boiler is one of a range of highly energy-efficient A-rated gas boilers from Worcester-Bosch.

These Boilers are highly rated by SEDBUK 2009.

The Worcester-Bosch Greenstar 24i System requires a hot water storage cylinder; however, it doesn’t require a feed and expansion cistern.

This makes the Greenstar 24i a quick and easy Boiler to install which can being down the installation cost, and this also makes it efficient and economical to run.

Main Features:

  • ERP rating: A HEAT
  • Efficiency Rating: 94%
  • Band Rating: A Rated
  • LPG Compatible: Yes
  • Standard Warranty: 5 Years
  • kW Options: 24.6 kW
  • Mounting: Wall-mounted

Why Second Spot?

These got 2nd place due to high scores in areas like; value for money and efficiency.

Worcester-Bosch Boiler Price:

The price comes in around £1,000 on average for these Boilers, with an installation price, being around £1,800 to £2,200. 

Brand: Vaillant

Model: Vaillant ecoTEC Plus System Boiler

Details: The Vaillant ecoTEC boiler range stands out as a superb, energy-efficient system boiler choice. It offers exceptional performance for both hot water and central heating, resulting in reduced energy costs for homeowners.

Boiler Sizes: The Vaillant ecoTEC series offers a variety of boiler sizes to suit different home requirements, including 12kW, 15kW, 18kW, 24kW, 30kW, and 37kW models. The 30kW model is particularly popular among consumers.

Smart Efficiency: The ecoTEC Plus boasts intelligent features; it can adjust its heating power to match your needs, utilizing only 16% of its maximum power when necessary, thereby saving fuel and money. Known for its efficiency, user-friendliness, reliability, and quiet operation, it’s a top choice for homeowners.

Premium Features: Featuring a straightforward backlit display and a stainless-steel heat exchanger, the ecoTEC Plus offers premium components that contribute to its status as one of the leading system boilers available on the market today.

Read more: Affordable Boiler Prices

Vaillant System Boilers Features:

  • For use with Unvented Systems.
  • Stainless steel heat exchanger
  • Advanced modulation during low usage to ensure maximum efficiency
  • New high-efficiency pump to reduce energy consumption
  • Stylish contemporary case design to ensure a seamless fit with home decor
  • ErP Compliant
  • Lightweight and compact
  • Natural Gas fueled
  • Includes 2 stage frost thermostat
  • Built-in pump and expansion vessel
  • Compatible with Unvented systems
Unvented Hot Water Cylinder Replacement in Barry

Why third place?

This boiler got 3rd place due to reasons such as; being an excellent boiler with reliable internal components meaning that you can’t go far wrong with the Vaillant EcoTec series system boilers.

Vaillant Boiler Price:

This boiler usually costs around £1500 with an installed price of £2000+

What’s the average cost of a system boiler in 2021?

The average system Boiler costs for 2021 is £1,750.

The low end of the range is around £1000, whilst the top end of the range are around £3000.

Remember that boilers are one of the most important features of your home in terms of use and cost, so picking the right one is important. 

If you need help making your decision feel free to contact us.


Different Types of Boiler Systems Explained – Best Heat Pumps, Brands & Pricing

There are two different types of heat pumps:

  • Ground Source Heat Pumps
  • Air Source Heat Pumps

What’s the difference?

Air Source Heat Pumps

The most common type of heat pump is the air source heat pump, which transfers heat between your house and the outside air.

An air source heat pump will extract heat from air outside your property in the same way a fridge extracts heat from its inside.

They still work in cold weather!

Air pumps become less efficient the cooler it is outside, but they can be capable of operating sufficiently in temperatures of -15 C, which is 99.99% of the year in the UK.

Ground Source Heat Pumps

A ground source, water source or geothermal heat pump functions similarly, but it functions by taking the residual warmth from the soil or a water body outside your property and moves it to the inside of the property.

These heat pumps achieve higher efficiencies by transferring heat between your house and the ground or nearby water source.

Lower Operating Costs:

Although they are more expensive to install they generally have lower operating costs because they can rely on more constant source temperatures.


The heat pumps have fantastic energy efficiency ratings and although they do have some impact on the environment (as they require electricity to run), they do not combust fuels directly, so in most cases they too, provide a fantastic way of lowering your carbon footprint.

As per some recent Boiler Guide Articles, please find the best heat pumps from each type:

Best air source heat pumps and prices

Please find details of best air source heat pumps as well as an estimate of the costs.

Typically the air source heat pumps or an average property would usually costs between £4,000 – £11,000*.

*Although in the UK you can currently get £5,000 contributed towards the cost.

Soon to start paying for itself…

This may sound like a big price tag but when you consider that it could be efficiently heating your home for around 20 years with reduced heating bills, it easy to see how it will soon be paying for itself.

Using the table below you can get a quick understanding of what each of the models has to offer before we go into more detail about each one individually.

Read about: The Best System Boiler Brands

ManufacturerModelAvailable Outputs (kW)ErP Energy Efficiency RatingPotential Price
DaikinAltherma 34, 6, 8A++£6,000 – £8,000
NibeF20408, 12, 16A+++£6,000 – £8,500
SamsungEHS Mono16A+++£1,750 – £4,000
VaillantaroTHERM5, 8, 11, 15A++£3,000 – £7,000
ViessmannVitocal 200-A2.6 – 11A+++£5,500 – £9,000
GrantAerona³6 – 16A++£4,000 – £7,000
MitsubishiEcodan QUHZ4.5A++£4,000 – £6,000
LGTHERMA V R325-16A++£4,000 – £6,000
HitachiYutaki S80211,14, 16A+++£4,000 – £6,000

Purchase Only Price:

The prices in the table above are estimates and do not include the cost of installation, which will vary depending on who carries out the work.


We highly recommend getting 3 quotes from different installers to give you the greatest chance of finding the best deal for your home.

We here at Let’s Heat can provide you with one of these quotes online now! Get a quote.

While it might feel that the costs are already beginning to add up, you can begin to make these initial costs back via reduced energy bills and Renewable Heat Incentive payments during the lengthy lifetime of an air source heat pump.

Brand: Daikin Altherma

Details: Over the past 90 years, Daikin have built up a worldwide reputation for the quality of their forward thinking air conditioning and climate control technology.

Heats your home even in cold climates:

The Daikin Altherma with Bluevolution Technology 3 is an air-to-water system that can operate in temperatures as low as -25°C which means your home will get heating from the air even in the depths of winter.

It is the first air-water heat pump in the UK using R32 as a refrigerant and achieves an overall seasonal efficiency of A++.

Get Smart

You also have the option of controlling your heating via an app on your smart device.


The indoor unit is designed for easy installation and maintenance as all the hydraulic components are accessible from the front. It needs to be combined with a separate domestic hot water tank with a capacity of up to 500 litres with or without solar support.


The outdoor unity has handles for easy installation as well as an out-blow grill and factory mounted suction grill as extra safety features.

Interested in Daikin Heat Pumps?

Discover and compare different air source heat pumps from Daikin here –


We here at Let’s Heat can provide you a quote online now! Get a quote.

Brand: Nibe F2040

Details: Nibe are a Swedish company that’s grown to become a leading manufacturer of domestic heating products in many countries across Europe.

The Nibe F2040 is a highly efficient air source heat pump shown through its ErP rating of A+++.

Easy Install

You won’t have to worry about the installation of this appliance as that’s been designed to be as smooth as possible, thanks to it being fitted with an anti-vibration water connection.

By downloading the Nibe Uplink app to your smart device, you can get quick overviews and status updates of the appliance and the heat it’s generating.

Innovative Alert System

Should there be an issue with your air source heat pump, which is very rare, then an alert will be sent to your device immediately.

Interested in Nibe Heat Pumps?

Discover and compare different air source heat pumps from Nibe here –


We here at Let’s Heat can provide you a quote online now! Get a quote.

Brand: Samsung EHS Mono

Details: You’re probably more familiar with Samsung’s phones than their air source heat pumps but after years of research, they’ve released the EHS Mono range.

Easy to install & quiet

The unit is compact and lightweight which makes them simple to install and you have the option of it being wall mounted or floor standing.

The EHS Mono is capable of achieving high water temperatures of 55°C and can still extract heat from the air in temperatures of -25°C.

It even operates quietly.

Interested in Samsung Heat Pumps?

Discover and compare different air source heat pumps from Samsung here –


We here at Let’s Heat can provide you a quote online now!

Brand: Vaillant aroTHERM

Details: Vaillant are a trusted manufacturer of gas boilers and also have a range of renewable products available from ground source heat pumps to solar thermal.

Easy Install & Quiet

Vaillant’s aroTHERM air source heat pump is a compact unit that makes installation easy.

The appliance comes MCS accredited and Quiet Mark approved as it ultra-quiet operation. It can be easily integrated into domestic heating systems which means that the installation will cause very little disruption.

To further improve performance and give extra protection from corrosion the unit has a blue fin coated evaporator with anti-hydro coating.

Interested in Vaillant Heat Pumps?

Discover and compare different air source heat pumps from Vaillant here –


We here at Let’s Heat can provide you a quote online now!

Brand: Viessmann Vitocal 200-A

Details: The Viessmann Vitocal 200-A is not only an air source heat pump but also said to be an ‘ornament for your garden’ thanks to its extremely modern design. The unit and can integrate with both new and existing heating systems.

Efficient & Quiet

It can achieve a maximum flow temperature of 65°C for heating as well as convenient domestic hot water heating. It does all of this while operating extremely efficiently and quietly while only incurring minimal electricity costs.

Not only can you rely on the Vitocal 200-A to heat your home, it’s also capable of reversed operation in the summer, meaning that it can cool your home during the warmer months and is compatible with energy from solar panels.

User Friendly Unit

The Vitocal 200-A is user friendly thanks to the Vitotronic control unit, featuring a plain text and graphic display plus the option of remote control with the ViCare app and Vitoconnect.

Interested in Viessmann Heat Pumps?

Discover and compare different air source heat pumps from Viessmann here –


We here at Let’s Heat can provide you a quote online now!

Brand: Grant Aerona³

Details: Grant’s range of MCS approved air source heat pumps is the Aerona³ and is the third generation of ASHPs by Grant. These pumps are single phase, DC inverter driven and have an ErP energy rating of A++.

Still Working in Cold Temperatures

They incorporate in-built weather compensation and a base tray heating element to prevent ice formation and can extract heat in temperatures as low as -20°C. Available outputs include a a 6, 10 or 16kW model as well as the new 12kW R32.

The Aerona³ 12kW R32 inverter driven air source heat pump is the latest addition to the range. It uses a more ‘environmentally friendly’ refrigerant (R32) which has a lower Global Warming Potential (GWP) rating than other typical heat pump refrigerants. It is the first monobloc R32 air source heat pump to be launched in the UK and is suitable for S-Plan heating control systems.

Interested in Grant Heat Pumps?

Discover and compare different air source heat pumps from Grant here –


We here at Let’s Heat can provide you a quote online now!

Brand: Mitsubishi Ecodan QUHZ

Details: The Ecodan QUHZ from Mitsubishi is a monobloc air to water heat pump system with a thermal store. It features low noise output and has a built in monitoring system to enable you to track and potentially reduce your energy use.

Hot Water too

This system includes an outdoor unit which only requires a supply of electricity and water and an indoor hot water cylinder (thermal store) which acts just like a standard hot water cylinder works alongside a boiler providing your heating and taps with hot water.

The Ecodan can be installed in new builds or alongside existing heating or in a hybrid system if you are keeping your gas boiler as a back up. This Ecodan system can be controlled using a wireless controller or via an app on a smart device.

Interested in Mitsubishi Heat Pumps?

Discover and compare different air source heat pumps from Mitsubishi here –


We here at Let’s Heat can provide you a quote online now!

Brand: LG THERMA V R32

Details: The THERMA V R32 air to water heat pump uses with R32 refrigerant, an environmentally sustainable refrigerant which has a Global Warming Potential 70? lower than that of R410A. It is a highly efficient model with a A+++ rating thanks to the Revolutionary Scroll Compressor.

The THERMA can operate in temperatures as low as -25°C and heats water to a maximum of 65°C. The user interface is intuitive enabling quick and easy use and lets you programme heating schedules based on your lifestyle.

Monitor your usage:

You can also monitor your energy consumption on a daily or monthly basis and control it remotely via the G SmartThinQ™ app on your smart device.

The THERMA is an all-in-one heating solution with 3 main components built-in to allow easy installation without additional refrigerant piping work and easy access for servicing.

Interested in LG Heat Pumps?

Discover and compare different air source heat pumps from LG here –


We here at Let’s Heat can provide you a quote online now!

Brand: Hitachi Yutaki S80

Details: Hitachi’s Yutaki-S80 high temperature heat pump produces hot water up to 80°C thanks to an energy-efficient, secondary Cascade R134a Heat Pump Circuit instead of an electrical element which gives a boost from 45°C to 80°C. It will operate all year-round even in temperatures as low as -20°C.

The Yutaki S80 has an energy efficiency rating of A+++ so will keep energy usage to an absolute minimum. It will provide both heating and hot water with a hot water recovery time which is the same as a traditional boiler.

Great for all properties

The S80 is ideal for new builds and replacing boilers in existing homes and even older properties where higher water supply temperatures may be required to keep the house warm. It is not intended to work in a hybrid system alongside a back up boiler.

Read more: Top UK Combi Boilers

Emergency Boiler Repair

Interested in Hitachi Heat Pumps?

Discover and compare different air source heat pumps from Hitachi here –


We here at Let’s Heat can provide you a quote online now!

Comparing air source heat pumps

When trying to choose the best air source heat pump for your home, there are several key features to consider apart from the price.

Types of air heat pumps

There are two types of air heat pumps to choose from: air to water or air to air.

  • Air to water heat pumps are the most popular as they pride heating and hot water.
  • Air to air heat pumps are less popular, as they only provide space heating and not hot water production.

There is also a difference between monobloc or split heat pumps which refers to how the system is set up in your home.

  • A monobloc has all of its components (apart from the hot water cylinder in your home) in one compact unit outside the home.
  • A split heat pump includes an outdoor with the heat exchanger and refrigerant as well an internal unit inside.

Most homes in the UK are ideal for a monobloc air to water heat pump, but a split system may be suitable for more complicated installations as it can be installed up to 30m away from the home offering a more flexible installation.

Energy Efficiency

Air source heat pumps are exceptionally efficient, as for every kW of energy they use, they generate three times as much usable heat.

While some heat pumps may be labelled with better efficiency ratings than others, it is important to remember that the actual efficiency you achieve will be greatly influenced by other factors like the level of insulation, the outside temperature, and your demand for hot water.


Air source heat pumps are available in a range of different outputs to suit different sizes of homes.

It is important to install the right output, but a professional heat pump installer will be able to advise you on this topic.

Is an air source heat pump right for your home?

There are various advantages and disadvantages associated with installing air source heat pumps. If you’re interested in the potential benefits these systems can offer your home, consider the following:

Reduced Energy Bills

Air source heat pumps are highly efficient heating systems, capable of significantly lowering your energy bills.

RHI Payments

Air to water heat pumps qualify for quarterly payments over 7 years through the Renewable Heat Incentive scheme, providing financial incentives for their installation.

Better for the Environment

Heat pumps consume minimal electricity and produce significantly fewer carbon emissions compared to fossil fuel heating systems, making them a greener choice for environmentally conscious homeowners.

Year-Round Heating

Air source heat pumps can effectively heat your home throughout the year, even during the coldest UK winters, ensuring comfort regardless of the season.

Easy Maintenance

Heat pumps require minimal maintenance, typically only needing annual servicing. They can operate efficiently with little intervention, contributing to hassle-free home heating.

Long Lifespan

Many air source heat pumps have a lifespan of up to 20-25 years, roughly double that of a modern boiler, offering long-term reliability and cost-effectiveness.

However, it’s essential to recognize that air source heat pumps may not be suitable for every type of home, so careful consideration is advised before installation.

For an air source heat pump to be effective your home needs to have conditions such as;

  • A high level of insulation
  • Outside space for the fan unit
  • Large radiators or underfloor heating for maximum heat delivery as heat pumps deliver heat at a lower temperature than boilers
  • A small amount of electricity to operate
  • A hot water cylinder

To get the best price on an air source heat pump for your home, it is important to compare multiple quotes from different companies.

This can take time but we can help make your research a lot easier.

We here at Let’s Heat can provide you a quote online now! Get a quote.

Which is the best ground source heat pump?

Best Ground Source Heat Pump: Viessmann Vitocal 222-G

According to another boiler guide article, one of the best ground source heat pumps available is the Viessmann Vitocal 222-G.

Heating & Hot Water

The Vitocal 222-G not only efficiently heats your property but also provides domestic hot water. It features an integral hot water cylinder with a capacity of up to 220 litres.

Ground Source Heat Pump with Cooling

Unlike some other renewable heating systems, the Vitocal 222-G offers cooling functionality during the summer months by utilizing the cooler underground temperatures.

Best Ground Source Heat Pump by Warranty

While the Vitocal 222-G has a warranty period of 2-5 years, there are models with longer warranty periods. For instance, the Vaillant geoTHERM boasts a parts and labor warranty of up to 7 years, making it a preferred choice for those prioritizing warranty coverage.

Comparing ground source heat pumps

To find the best ground source heat pump for your property, it’s important to consider the following:

  • Output rating
  • Unit Dimensions
  • Length of the warranty period
  • Efficiency rating
  • Potential cost
  • If it’s Microgeneration Certification Scheme (MCS) certified – required for Renewable Heat Incentive eligibility

Best ground source heat pumps and prices

In the table below, we’ve compared key information about the best ground source heat pump models side-by-side.

ManufacturerModelAvailable Outputs (kW)ErP Energy Efficiency RatingPotential Price
VaillantgeoTHERM22, 30, 38, 46A++£8,000 – £12,000
ViessmanVitocal 222-G6.1 – 10.0A++£6,000 – £7,500
NibeNibe F11455 – 17A+++(17kW – A++)£9,000 – £10,000
KensaEvo7, 9, 13, 17A++£8,000 – £12,000
Worcester-BoschGreenstore 6 System6, 7, 9, 11A+£4,500 – £8,000

The above ground source heat pump prices are estimates but many ground source heat pumps tend to cost £8,000 to £12,000 to buy and install.

Nibe ground source heat pumps

A Nibe heat pump could potentially lower your energy bills by as much as 75%.

This is thanks to the minimal amount of electricity that is required to power the heat pump during operation.

Nibe ground source heat pumps are split into 2 ranges:

  • The F Series
  • The more recent S Series.

1. Nibe S Series

  • Output ratings from 6 kW up to 25 kW
  • Integrated wireless connectivity
  • User-friendly touchscreen display
  • Use the uplink app to control the heat pump from your smartphone
  • Automatically adjust the heating based on the weather conditions
  • Integrated hot water heater (180 litres)
  • Also boasts cooling technology
  • Can be used with voice assistant
Nibe S Series Heat PumpsOutput Ratings (kW)EfficiencyWarranty
S12556, 12, 16A+++2 -7 years
S11556, 12, 16, 25A+++2-7 years

2. Nibe F Series

  • Operational costs are kept to a minimum
  • Smart energy-saving technology
  • Outputs ranging from 5 kW up to 60 kW
Nibe F Series Heat PumpsOutput Ratings (kW)EfficiencyWarranty
F12556, 12, 16A+++2-7 years
F11556, 12, 15A+++2-7 years
F11456, 8, 10, 12, 15, 17A+++2-7 years
F135528, 43A+++2-7 years
F134524, 30, 40, 60A+++2-7 years

Vaillant ground source heat pumps

The most popular Vaillant ground source heat pumps are in the geoTHERM range.

However, they also manufacture a diverse range of flexoTHERM multi source heat pumps which can be adapted to take heat from the air or water as well as the ground.

Quite Pumps

These heat pumps are amongst the most quiet during operation and have been awarded Quiet Mark accreditation as a result.

Vaillant Ground Source Heat PumpsOutput Ratings (kW)Efficiency RatingWarranty
geoTHERM22, 30, 38, 46A++Up to 7 years
flexoTHERM multi source5, 8, 11, 15, 19A+++5-7 years

Viessmann ground source heat pumps

Viessmann have an extensive range of ground source heat pumps to choose from with outputs from 5.6 kW all the way up to 96.1 kW.

Their Vitocal range of heat pumps offer a number of benefits for new builds, semi-detached, detached homes and larger residential properties.

Hot Water

If you’re looking for a heat pump that can meet your domestic hot water demands then the Vitocal 222-G has an integral hot water cylinder.

Viessmann Ground Source Heat PumpsOutput Rating (kW)Efficiency RatingWarranty
Vitocal 200-G5.6, 7.5, 9.7A++5-7 years
Vitocal 222-G5.8, 7.5, 10.4A++5-7 years
Vitocal 300-G5.7, 7.6, 10.4, 13, 17.2A++5-7 years
Vitocal 350-G25.4, 34.7, 42.2, 52.3A++5-7 years
Vitocal 350-G Pro27.2, 34.3, 56.1, 76, 96.1A++5-7 years

Mitsubishi ground source heat pumps

Mitsubishi Ecodan Monobloc heat pumps can take heat from the ground or a water supply, such as a lake.

These are powerful models with outputs of 45 kW and 60 kW that can be installed as single modules or stacked together to increase the power output (up to 960 kW).

The system delivers water flow temperatures of up to 65°C and is MCS certified which means that it’s eligible for the Renewable Heat Incentive.

Mitsubishi Ground Source Heat PumpsOutput Rating (kW)Efficiency RatingWarranty
Ecodan Monobloc45, 60A++3-7 years

Worcester Bosch ground source heat pumps

These heat pumps are available as either combination (combi) or system models.

All models in the combi range have an integrated hot water cylinder (185 litres) for domestic hot water storage.

Meanwhile, the system range of heat pumps require you to have a separate hot water cylinder* installed.

*It is important to note that this hot water cylinder must be heat pump compatible.

Worcester Bosch Ground Source Heat PumpsOutput Ratings (kW)Efficiency RatingWarranty
Greenstore LECP Combi5.4, 6.6, 8.7, 10.2A+ 
(Greenstore 11 – A++)2 years  
Greenstore LECP System5.4, 6.6, 8.7, 10.2A+ 
(Greenstore 11 – A++)2 years  

Kensa ground source heat pumps

Kensa offers a fairly extensive range of ground source heat pumps.

Output ratings ranging from 3 kW up to 30 kW are available across 3 ranges: Evo, Shoebox and Twin Compact.

5 year warranty

All of Kensa heat pump ranges are highly efficient, come with a warranty of 5 years and are eligible for RHI payments.

The main difference is price. Shoebox heat pumps are the most affordable (from £3,510) while the Twin Compact range has the highest price tag (from £9,230).

Evo Heat Pumps

Evo heat pumps sit in between with prices of the models in this range starting at £5,862.

A key benefit of all single-phase Kensa heat pumps are the electrical ‘soft starts’ which ensures that energy consumption is kept to a minimum during start-up.

Kensa Ground Source Heat PumpsOutput Ratings (kW)Efficiency RatingWarranty
Evo7, 9, 13, 15, 17A++5 years
Shoebox3, 6A+5 years
Twin Compact12, 15, 16, 17, 20, 24, 30A++5 years

Ground source heat pump installation costs

Ground source heat pumps aren’t the most affordable heating systems. And installation is fairly complex which means that the installation costs can be fairly high too.

Price range:

The total cost of installing a ground source heat pump can come to between £10,000 and £18,000. In some cases, these costs can stretch to over £30,000.

However, while high, these prices don’t tell the whole story. This is because you will likely be making significant energy bill savings and could also be receiving RHI payments.

Existing SystemEnergy Bill Saving per yearRHI Payment (1 January – 31 March 2018)
Gas Boiler (G-rated)£505 – £580£2,335 to £2,750
Gas boiler (A-rated)£65£2,335 to £2,750
Oil boiler (G-Rated)£900 to £1,110£2,335 to £2,750
Oil boiler (A-rated)£570 to £665£2,335 to £2,750
LPG boiler (G-rated)£560 to £665£2,335 to £2,750
LPG boiler (A-rated)Increase of £55 to £65£2,335 to £2,750
Coal£525 to £645£2,335 to £2,750

All Boiler Types: modern boiler systems

Confirmation of the four main types of boilers and heating systems:

  1. The Common, Heat Only Boiler
  2. A System Boiler
  3. Combi Boiler, Condensing Boiler
  4. The new Heat Pumps!

The boiler installation & repair team here at Let’s Heat, are all fully qualified to the highest standards and take pride in producing exemplary work standards which include completing all boiler installation requirement no matter what time or day this is required!

Experts doing excellent work

Our team of high quality professional engineers have an extremely high 4.9 out of 5, Trustpilot score given by our previous happy customers and we are fully accredited by Gas Safe and Corgi registered, as well as FCA approved for all of our financial transactions.

Different Types of Boiler Installations explained…

There are three main types of boiler installation and each has a different level of complexity which can impact the boiler installation times:

  1. Straight Swap
  2. Boiler Relocation
  3. System Upgrade

Please find more details about each type of installation as well as an estimate of the time each type of installation will take:

Read about: Boiler installation in Southampton

New Boiler installation

Type of installation: Straight swap (same location)!

Type of Installation: Straight Swap (Same Location)

Details: A straight swap installation, also known as a like-for-like swap, involves replacing your current boiler with one of the same type in the same location within your property.

Time: This type of installation is typically the quickest, often completed in just one day due to minimal changes required.

See boiler prices for the costs of your new boiler and boiler installation.

Type of Installation: Boiler Relocation

Details: A boiler relocation installation entails moving your new boiler to a different location within your property. This may involve adjustments to existing pipework or the installation of new elements.

Time: This adjustment could extend the installation process to up to 2 days. The further the new location, the longer the installation may take, impacting the overall cost.

See boiler prices for the costs of your new boiler and boiler installation.

Type of Installation: System Upgrade

Details: System upgrade installations involve changing the type of boiler installed in your property. For example, upgrading from a heat only boiler to a combi boiler.

Time: System upgrades can take up to 3 days or more, depending on complexity. Despite the longer process, the benefits of a more efficient system often justify the duration.

See boiler prices for the costs of your new boiler and boiler installation.

Why choosing the right boiler is important?

Choosing a suitable boiler for your home can provide you with all the heating and hot water that your family or property require.

You could also save money on your annual energy bills and reduce your carbon footprint by using a more efficient system for your requirements.

Energy regulations…

Over the last few years, the UK has passed several government guidelines for boiler replacement and energy efficiency, which now need to be adhered to for all boiler replacements, so please remember:

  • If you have a gas boiler, it must have at least a 92% ErP efficiency regardless of boiler type.
  • A Combi boiler installation requires one energy-saving feature
  • You must have functioning time and temperature controls

Finance for your boiler replacement or heat pump…

Buying a new boiler and having a boiler installation or a heat pump, is an investment. However it can be expensive, especially paying for it all in one hit.

If you haven’t got the money on hand for the boiler and installation services that you require, you can get the job done on a finance package that is FCA-approved.

We can also offer a number of split payment options for you to consider.

Boiler Replacement Payment Options

For new boiler installation, you can pay by card, pay zero deposit, and pay monthly over 2 to 10-years or take our a finance package.

So why Let’s Heat for your boiler replacement?

A. Let’s Heat Are Quality & Accredited Boiler Installers

Let’s Heat professional engineers and emergency plumbers provide a professional and reliable emergency plumbing and heating service.

This service includes Boiler Installation and Heat Pump Installation, in Cardiff and the surrounding CF postcode areas of South Wales.

We also cover the rest of Wales and all of England (see below).

Qualifications & Accreditations:

Our team of high-quality professional engineers has an extremely high 4.9 out of 5, Trustpilot score given by our previous happy customers and we are fully accredited by Gas Safe and Corgi registered, as well as FCA approved for all of our financial transactions.


All of our staff at Let’s Heat are experts in their field and have gathered many years of experience, working on a wide selection and variety of emergency plumbing and heating solutions and services throughout Cardiff, the rest of Wales & the UK.

B. Because we care…

Are you still a little confused about where to start or who to use?

Our easy-to-use online questionnaire will guide you through everything that you, and we, need to know in order to ensure that you have the correct solution for your needs.

We will also ensure that you are completely satisfied with the solution offered prior to completing any works.

Why else?

  • Cover Cardiff and surrounding areas of South Wales
  • We are reliable, professional, and trustworthy
  • High Trustpilot score of 4.9 out of 5.
  • Gas Safe Accredited (corgi registered),
  • Our finance is FCA accredited
  • Our prices are very competitive
  • We ensure that your house is kept clean and tidy during any work
  • Our workmen use floor protection on each job
  • We always make sure your rubbish is correctly disposed of
  • Our Service comes with a 12-month snag guarantee
  • We travel anywhere throughout the UK

You can research your boiler replacement requirements and choose your new boiler and the boiler installation online, without leaving the house…

If you need a new boiler or heat pump and installation, don’t hesitate to reach out to our award-winning heating engineers team for more information.

If you would like a new boiler or heat pump then you can get everything, including the full boiler replacement from Our Let’s Heat Team.

365 & 24/7

We replace boilers and install heat pumps nationwide and include next-day installation (on orders placed before 12/2 pm in Spring/Summer or Autumn/Winter.

We are experienced and knowledgeable in all aspects of heating installation services and repair and maintenance, so if you have any further questions please feel free to contact us.

The full range of heating & plumbing services provided by Let’s Heat are as follows:

  • Boiler Repairs & Installations
  • Boiler Supply & Fit
  • Financing Your Boiler
  • Emergency Boiler Repairs & Installations
  • Emergency Boiler Supply & Fit
  • Plumbing Repairs
  • Bathroom Plumbing
  • Kitchen Plumbing
  • Emergency Plumbing Repairs
  • Bathroom Plumbing in Emergencies
  • Emergency Kitchen Plumbing
  • General Plumbing Services
  • Emergency Plumbing Services
  • Emergency Gas & Heating Engineer

Areas covered by our Boiler Replacement Services:

Let’s Heat engineers cover all of Wales and England.


Let’s Heat offers Heat Pump installations across Wales, including regions such as South East Wales, South Wales, South West Wales, Mid Wales, East Wales, West Wales, and North Wales.

This encompasses all Welsh cities, including Cardiff, Newport, Swansea, and all other towns and cities in Wales.


Let’s Heat provides Heat Pump installations throughout England, covering areas such as South West England, South East England, East Midlands, West Midlands, North West England, and North East England.

This includes major English cities like London, Reading, Southampton, Portsmouth, Bristol, Exeter, Plymouth, Gloucester, Swindon, Oxford, Leicester, Nottingham, Derby, Birmingham, Worcester, Wolverhampton, Walsall, Liverpool, Manchester, Leeds, York, Sheffield, Newcastle, Sunderland, Middlesbrough, and more.

Any more questions?

If you have any further questions about Heat Pumps or Boilers, please see our FAQ Page.


How many types of boilers are there?

There are four main types of boiler systems or heating systems that we recommend and install at Let’s Heat. these are: The Common (Heat Only Boiler), A System Boiler
Combi Boilers and Heat Pumps!

What is the best boiler brand in the UK?

#1. Viessmann Combi Boilers.
#2. Alpha Combi Boilers.
#3. Vaillant Combi Boilers.
#4. Worcester Bosch Combi Boilers.
#5. Ideal Combi Boilers.
#6. BAXI Combi Boilers.

How much is a combi boiler in UK?

A new combi boiler would cost £600 – £900 for a budget model, £900 – £1,200 for a mid-range model and £1,000 – £2,000 for a premium model depending on the size of the boiler.

what’s the difference between ground and air heat pumps?

The main difference between the two types is simply where they get heat from: air source heat pumps (ASHPs) absorb heat from the air while ground source heat pumps (GSHPs) absorb heat from the ground.

Is air or ground heat pump better?

A ground source heat pump is usually more efficient than an air source heat pump, and it has better RHI payback. On the other hand, a ground source heat pump is more costly to buy and install.