Monobloc Heat Pumps in the UK: Prices, Types & Benefits (2025)

Are you considering getting a heat pump but concerned about where you'll find the home space? Don't stress because a monobloc heat pump packages all the necessary components to run a heat pump in one compact unit. 

In the article, we'll explore everything you need to know about these renewable heating systems, how they operate, and the price you can expect to pay. We can even help you secure a reliable installer with a good deal for your project. 

You can do this by using GreenMatch's free quotes service. It's a free and fast way to get your hands on tailored quotes from the best installers. Save yourself hours of researching, and instead fill in one form to get up to 4 quotes directly. To get started, click the button below. 

A monobloc heat pump is an air to water heat pump made of one unit. This compact system contains all the essential components that make up a fully functional heat pump, including the heat exchanger, evaporator, condenser, compressor, and expansion valve.

From this single outdoor unit, monobloc heat pumps can provide heating, cooling and hot water to your home in the same way as a regular mini split heat pump system, just without the additional indoor unit. 

Usually, an indoor unit transfers the heat energy captured by the outdoor unit to your home's central heating system, such as your radiators, air conditioning units, or underfloor heating. 

Monobloc heat pumps bypass the need for any indoor components, instead connecting directly to your heating system. Because of this, they should be positioned against the outside wall of your home, as close as possible to the hot water cylinder. 

One of the main benefits of monobloc heat pumps is that they save interior home space, making them especially suited to smaller homes. 

Given how much power is packed into a monobloc unit, they can be much larger in size than a split system, which is made up of two smaller units. Therefore, you will need to reserve some outdoor home space for the unit itself, and some decent airflow around the unit while it operates to help prevent overheating. 

Monobloc heat pumps work in the same way as all air source heat pumps: by absorbing thermal energy from the outside air. 

This thermal energy is transferred into a refrigerant via the heat exchanger. The refrigerant is then vaporised via the evaporator, and compressed to increase its temperature and pressure, via the compressor. 

The heated refrigerant can then be used to heat up your home's water supply. From here, it can be sent through your home's central heating system and released for heating, cooling, or domestic hot water. 

The vapour passes through the expansion valve to reduce the pressure before it's cooled back into a liquid, and the cycle begins again. 

Both types of air source heat pumps share the same fundamental components, but they differ in how they transfer heat. A split system consists of two separate units connected by pipes that circulate refrigerant between them. 

The outdoor unit absorbs heat from the air, while the indoor unit transfers this heat into the home’s heating system. This is also where the compression stage would usually take place.

In contrast, a monobloc unit features a self-contained, closed-circuit refrigerant system and connects directly to the home's water supply, much like a traditional gas boiler.

It's possible to install monobloc ground source heat pumps and even water source heat pumps, although, on a technicality, they can still be considered split since both systems require some additional underground ground loops to extract heat energy. 

Ground source heat pumps 

Monobloc ground source heat pumps require a connection to a ground loop system which is buried underground. Fluid is pumped through these pipes, absorbing geothermal heat energy as it travels. It will then transport this heat to the outdoor unit, which houses all the components needed to evaporate and condense this heat for your home's needs. 

Water source heat pumps 

Monobloc water source heat pumps are similar to ground source heat pumps, but instead, they extract heat from a water source like a lake or a river. A mixture of water and antifreeze circulates through coils or heat exchange panels that have been submerged in the water source, absorbing heat energy before being sent to your home via the outdoor unit. 

Monobloc air source heat pumps cost an average of £8,000 – £15,000. The average UK home with 3 – 4 bedrooms will require an 8 - 13 kilowatt (kW) heat pump, which will cost £11,500. The table below gives you a closer look at these prices. 

This total cost includes the cost of the technology device, the installation costs, and the associated ancillary costs. Estimated costs for high and low-temperature heat pumps, new builds and retrofit installations. 

Compared to a split system, monobloc heat pumps are generally cheaper to buy and install since it's far simpler to install one unit than two. That being said, month-to-month energy costs might be higher with a monobloc system because it will require more electricity to power a single-unit heat pump. 

Want to get the best deal on your air source heat pump installation without the hassle? The key is to compare quotes from top-rated installers. By doing so, you not only secure competitive pricing but also ensure your project is handled by a certified professional.

Instead of spending hours searching for the right installer, let GreenMatch do the work for you. Our smart comparison service connects you with up to 4 vetted professionals who match your specific needs.

Just fill out a quick form, and you'll receive tailored air source heat pump quotes—completely free and with no obligation. 

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Monobloc heat pump units should be positioned on an outside wall, as close to your hot water cylinder as possible, to allow easy connection between the two. 

This positioning is important since it limits the pipework's exposure to outdoor temperatures, which will help prevent water travelling through the pipes from freezing. Anti-freeze may be required to insulate the unit itself, otherwise the water it contains is at risk of freezing. 

The entire installation process can be summarised as follows: 

Once your monobloc system is installed, you can enjoy some highly efficient renewable heating, reduced energy bills, and the knowledge that you're contributing to a cleaner, greener environment. 

Installing a monobloc heat pump for your home can be much simpler than installing a traditional heat pump, thanks to having fewer components to install and connect. Thus, you can expect to pay less in fitting costs. 

Another smart way to keep installation costs down is by comparing offers from the best heat pump installers around. This way, you can be sure that you're handing your project over to a qualified professional while benefitting from the best rates. 

Making a shortlist of the best installers can take hours upon hours unless you do it through GreenMatch. Our exclusive comparison service is the best way to quickly connect to vetted professionals! 

Simply fill in the form, and we’ll connect you with up to 4 installers who have been matched to your needs. It's free, fast, and completely non-binding.