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Last updated: 24 March 2022

Air Source Heat Pump Installation - Complete Guide in the UK

Air Source Heat Pump Installation

Air Source Heat Pump - How Does the Installation Process Work?

As with any home improvement project, an air source heat pump installation process has a set of steps. While every home requires customisation, we have a guide to explain the basic process of installing an air source heat pump and guide you through the steps before, during and after the installation process.

Air source heat pump is a low carbon heating technology that is growing in popularity in the UK. An air source heat pump has many advantages for your home and for the environment. With a huge focus put on encouraging energy efficient renewable systems and banning gas boilers, heat pumps have come into the limelight and will continue to be there in the future.

The process of installing an air source heat pump can be slightly different depending on whether it’s a retrofit or a new build. However, there are 3 main steps involved in the whole process:

  • Pre Installation - onsite survey and assessing the suitability
  • Installation - installation indoor and outdoor units, and connecting them
  • Post Installation - finishing and maintenance

Air Source Heat Pump Installation Diagram

This diagram below illustrates the installation process of an air source heat pump. The initial process remains the same whether you choose to install an air to air heat pump or an air to water heat pump. The system consists of a standard outdoor unit that is installed outside a home and is used to draw warm air in. The indoor units vary depending on the type of air source heat pumps and can either be connected to radiators, underfloor heating or an air conditioning unit.

Installation Diagram

Pre-Installation Work: On-site Survey and Preparation

The first step after you have chosen an installer is that they will conduct an onsite inspection to check the suitability of your property in order to install the chosen heat pump. They are also trained to safely remove any existing system such as a gas boiler. Heat loss calculations will be made to determine the size of the heat pump that needs to be installed. The inspection is an important step in planning the installation correctly.

Once this is done, the installer will prepare a report with sketches of the property for efficiency installation of the system. Depending on the size of your home, heating needs and how well your home is insulated, the installer will recommend an appropriate type and size of an air source heat pump.

Installation: Indoor and Outdoor Units

Air source heat pump installation is a relatively uncomplicated process as the heat pump controls and pipework are similar to traditional boilers. The system consists of indoor and outdoor units that need to be installed.

The outdoor unit is the large unit outside the house that you can typically see. This unit sources air from outside and compresses it into warm air. The indoor units are then installed and connected to either radiators, underfloor heating or hot water pipes.

While installing the outdoor unit, the installer will make sure to choose an area where there is ample airflow with minimal obstructions. The unit will be bolted to the ground and the installer will secure it with brackets so that it does not move.

Connecting the Units

The indoor cylinder and the outdoor unit need to be wired and connected. The indoor unit will be connected to the radiators and other units where heat is released from within the house. Depending on your home and the distance between the indoor and outside units, wiring will need to be made by usually drilling a hole in a wall. Your installer will then connect them through refrigerant lines and electrical wires.

Post-Installation Work - Finishing and Maintenance

Once the installation has been completed, there will be some finishing fixes to be made to ensure the efficient working of the heat pump system. Most air source heat pumps come with sensors, so these need to be installed so that the heat pumps can send temperature signals to your thermostat.

At this point in time, you can also talk to your installer about the maintenance requirements. Though air source heat pumps have low maintenance requirements, it is advised to keep checking the filters and cleaning the fans from time to time. This can be done by your installer regularly to ensure that the heat pump is running efficiently throughout its long lifespan of around 20 years.

How Much Does an Air Source Heat Pump Installation Cost?

The cost of installing an air source heat pump typically costs between £8,000-£18,000. This cost is determined by various factors such as the size of the pump, type and the complexities involved in the installation process. If you are looking to install an air source heat pump along with similar home improvement projects such as underfloor heating or new air conditioning units, the installation cost can be lower.

Air Source Heat Pump Installation Cost

Total Cost: £8,000 - £18,000

Time taken for Installation: 2-5 days

Lifespan of an Air Source Heat Pump: c.a 20 years

What are the Funding Options in the UK?

The cost of installing heat pumps is becoming more affordable with grants and incentives introduced to promote low carbon technologies. The Renewable Heat Incentive is one such funding option where you can earn money through annual payments over a period of seven years. The upcoming Clean Heat Grant, which is expected to be released in April 2022 is a replacement for the RHI.

In the UK, heat pumps are expected to be the most efficient replacement to traditional fossil fuels in order to reduce greenhouse gas emissions. The Heat and Buildings Strategy is also expected to release this autumn, and will provide plans on incentivising homes to make the switch to low carbon heating systems, both in new builds and retrofits.

Renewable Heat Incentive - A guide to the Domestic RHI

Can You DIY Air Source Heat Pump Installation?

Installing a heat pump includes several steps and not all of them can be installed yourself. In order to reduce the installation cost you can choose to install the outdoor and indoor units yourself, although this may require some experience.

However, in order to connect the units and wiring them, you will need to get it done by a certified installer with trained experience, as it can be a complex process. Since the lifespan of an air source heat pump spans over two decades, it is best to invest in proper installation that will not cause problems over the years. This is where it becomes important to have a licensed electrician and installer do this for your home. Moreover, in order to be eligible for the RHI, it is essential to get your heat pump installed by an MCS certified installer.

How Long Does it Take to Install an Air Source Heat Pump?

It can take between 2 - 5 days to install an air source heat pump depending on the complications that may occur during the installation process. You will not be disturbed for long as part of the installation is done outside the house.

Most heat pumps also do not require planning permissions but it best to get this checked before installing it in your home. If you’re a small property the installation can even finish within one day, so it ultimately depends on your specific property.

How to Choose the Right Heat Pump Installer?

Choosing the right heat pump installer is one of the most crucial decisions to make as they will stick with you during the lifespan of your heat pump. Also, it’s essential to make sure the installer is certified and has good customer service post installation. For this reason, it is recommended to compare different installers and their offers before you choose the right one that meets all your requirements. In our video below, we provide you with a guide on how to choose the right installer based on 5 questions that you can ask them before making a decision:

Choosing a Heat Pump Installer - 5 Questions to Avoid Costly Mistakes
Valli Vishnubhotla
Written by Valli Vishnubhotla, Content Writer

Valli is a content writer at GreenMatch since 2017. She has been writing well researched articles about renewable energy, sustainability and green technologies. She has experience and knowledge about renewable energy products and stays on top of green energy trends. With over 5 years of expertise in the field, her work has been published in various media such as Entrepreneur, Business Insider, Canadian Geographic, uSwitch , and eCycle. The UK government sites have also made use of her work within their publications.