A ground source heat pump (also known as a geothermal heat pump) is a low‑carbon heating system that captures shallow heat from the ground to warm your home and provide hot water. In the UK, air source heat pumps are better known, but ground source systems are another option worth understanding, particularly for homes with enough outdoor space and the right ground conditions.
Ground source systems are still relatively rare. According to the MCS Data Dashboard, there have been just 13,764 MCS-certified domestic ground source heat pump installations in the UK between 2009 and September 2026.
This guide explains how ground source heat pumps work, what installation involves, how much they can cost, what grants may be available, and the main advantages and limitations to consider when comparing them with air source systems. If you’re new to the technology, it’s worth starting with our guide to how heat pumps work.
Ground source heat pumps warm your home and provide hot water by using heat collected through underground pipework. According to the UK government’s review of ground source heating, they are a low-carbon heating option that can help reduce energy bills and may be suitable for both existing homes and new-build properties. However, they generally require more outdoor space than other heating systems, so it is important to understand whether your home is suitable before moving ahead. They’re one of several types of heat pump available to UK homeowners.
Ground source heat pumps collect heat through pipes installed beneath the ground on your property. Depending on the available space and ground conditions, these pipes may be laid horizontally in trenches or installed vertically in deep boreholes. The Welsh Government’s advice note on heat from the ground gives a useful overview of both approaches.
The pipework contains a circulating liquid, typically a blend of water and antifreeze, which absorbs naturally stored heat from the surrounding ground.
This captured heat is then transferred to the heat pump via a heat exchanger. The system uses a refrigerant and compressor to increase the temperature of the heat, before delivering it to your home’s heating and hot water system. In the UK, ground temperatures remain relatively constant, which is ideal for efficient operation year‑round. For a more technical explanation, see the Environment Agency’s good practice guide to ground source heating.
Step 1: Heat is absorbed from the ground. Fluid circulates through buried pipework.
Step 2: The heat pump raises the temperature. Refrigerant and compressor technology concentrate the heat.
Step 3: Heat is delivered into the home to radiators, hot water cylinders and underfloor heating.
There are two main types of ground source heat pump systems: horizontal ground loops and vertical borehole systems. The right option depends on the amount of outdoor space available, the ground conditions at your property, and the type of installation your home can accommodate.
The installation process begins with a home suitability assessment. A professional installer will carry out a heat loss survey, a property assessment, and a review of your outside ground conditions.
This home suitability assessment informs the system design, which size of system you need and which configuration: loop or borehole.
Once this is decided, the installation begins, which involves excavation or drilling, pipe installation, heat pump installation, and integration with heating systems. This comes to commissioning, testing, system performance checks and a handover to you as the homeowner.
It’s important to understand that installation is generally more complex than replacing a boiler and timescales vary depending on the system type. That’s why it pays to work with an experienced, vetted installer.
One of the biggest questions homeowners have is the ground source heat pump cost. While these systems can be highly efficient, they generally have higher upfront costs than traditional heating systems and air source heat pumps.
The total cost will depend on factors including the size of your home, your heating requirements, ground conditions, and whether you install horizontal loops or boreholes.
Ground source heat pump installation costs vary significantly from property to property. In general, horizontal loop systems are less expensive because they require trenching rather than deep drilling, while borehole systems usually cost more due to the specialist equipment needed.
As a guide, a typical ground source heat pump installation can cost tens of thousands of pounds before any grants are applied. Government data from the Boiler Upgrade Scheme shows median installed costs around £23,000–£27,000 before grant, with half of installations falling roughly between £18,000 and £42,000 depending on complexity.
More recent figures from the MCS Data Dashboard suggest costs have continued to rise. Between January 2025 and September 2026, the average cost of an MCS-certified domestic ground source installation was £28,182 in 2025 and £30,544 in 2026.
Once installed, ground source heat pumps can be cheaper to run than oil, LPG or direct electric heating, and can be competitive with gas depending on your electricity tariff, insulation levels and how much heat your household uses. If you currently heat your home with oil, our heat pump vs oil boiler comparison looks at the running costs in more detail.
Running costs will depend on factors such as your home’s insulation levels, how much heat your household uses, electricity prices, and the efficiency of the system itself.
Homes that are well insulated generally get the best performance from heat pumps because they retain heat more effectively.
Ground source heat pumps are generally considered low‑maintenance systems, but regular servicing is still recommended to keep them operating efficiently.
An installer can check components such as the heat pump unit, controls and circulation systems to ensure everything is working correctly. Maintenance checks should be undertaken periodically in accordance with the manufacturer’s requirements, with annual checks commonly recommended to log ground‑loop temperatures and compare against previous years. Our guide to heat pump servicing explains what a typical service involves.
The heat pump itself can often last 15–25 years or more when properly maintained, while the underground pipework and boreholes may last considerably longer – commonly at least 50 years if sited away from unstable or contaminated ground and tree roots.
The upfront cost of a ground source heat pump can be significant, but financial support is available to help make installation more affordable.
If you live in England or Wales, the Boiler Upgrade Scheme (BUS) is currently the main government support programme available to homeowners.
Eligible households can receive a grant towards the cost of installing a ground source heat pump, helping to reduce the initial investment required. The standard grant is £7,500, and from 21 July 2026 to 31 March 2027, eligible off‑gas‑grid properties replacing oil or LPG heating can receive £9,000.
The grant is usually applied by the installer and deducted from the overall installation cost.
Eligibility requirements can change over time, so it’s always worth checking the latest Boiler Upgrade Scheme guidance on GOV.UK before making any decisions.
Depending on where you live, there may be additional support schemes available.
Homeowners in Scotland may be eligible for different grants or loan schemes through national energy programmes. Some local authorities and community energy initiatives may also offer support for low‑carbon home improvements.
As funding schemes are regularly updated, it’s a good idea to check what is currently available in your area before starting a project.
Both ground source and air source heat pumps provide low‑carbon heating and can help reduce reliance on fossil fuels. However, they suit different types of properties and budgets.
Ground source heat pumps are often slightly more efficient because underground temperatures remain relatively stable throughout the year.
Air source heat pumps extract heat from the outside air, which means they have to work with larger temperature variations during colder weather.
Both systems can perform well in UK conditions as long as they’re correctly designed and installed.
One of the main differences is cost.
Ground source heat pump systems generally have higher installation costs because of the excavation or drilling work required. Air source heat pumps are usually less expensive to install and involve less disruption to the property.
This makes air source systems more accessible for many homeowners, particularly where budgets are limited. Joining a group-buying scheme such as Switch Together’s heat pump scheme can also help bring the upfront cost down.
If you’re wondering how much space does a ground source heat pump need, the answer depends on the type of system being installed.
Horizontal ground loops require a sizeable outdoor area. As a rule of thumb, the Energy Agency’s guide to ground source heat pumps suggests around 10 metres of trench per 1 kW of heating load for slinky coils, or roughly 35–60 m of pipe length per kW for straight pipes. Borehole systems need much less surface space because the pipes are installed vertically underground.
Air source heat pumps typically require only enough space for an external unit mounted outside the property, making them suitable for a wider range of homes.
A ground source heat pump may be a good option if you have enough outdoor space, are planning a long‑term home improvement project, and want a highly efficient heating system.
An air source heat pump may be a better fit if outdoor space is limited or if you are looking for a lower upfront installation cost.
Ultimately, the right choice depends on your property, budget and heating needs.
Ground source heat pumps can be an excellent option for some properties, but they are not the right solution for every home.
A ground source heat pump could be a good fit if:
Like all heating options, there are also some ground source heat pumps disadvantages to consider.
The higher upfront cost can be a barrier for some households, and installation can be more disruptive than other heating upgrades because of the excavation or drilling involved.
Properties with very limited outdoor space may also find it difficult to accommodate a system.
Carefully assessing your property and speaking with qualified installers can help determine whether a ground source heat pump is a practical choice for your home.
Ground source heat pumps are designed to last for many years. The heat pump unit itself can often operate for 15–25 years or more when properly maintained.
The underground pipework and boreholes usually have an even longer lifespan and may continue functioning for several decades – commonly at least 50 years if sited away from unstable or contaminated ground and tree roots.
Yes. One of the advantages of ground source systems is that underground temperatures remain relatively stable throughout the year.
Because the ground does not cool down as quickly as the air during winter, the system can continue extracting heat even during colder weather.
Yes. A ground source heat pump can work with radiators, underfloor heating and hot water cylinders.
In some cases, older radiators may need to be upgraded to ensure the system operates as efficiently as possible, particularly if they were designed for high‑temperature boiler systems. Our guide to heat pump radiators explains what to look for.
The amount of land required depends on the type of installation.
Horizontal ground loops require a larger outdoor area because trenches need to be dug to accommodate the pipework – as a rule of thumb, around 10 metres of trench per 1 kW of heating load for slinky coils, or 35–60 m of pipe length per kW for straight pipes. Borehole systems require much less surface space because the pipes are installed vertically underground.
If you’re asking how much space does a ground source heat pump need, a professional site assessment is the best way to determine what is possible for your property.
For suitable properties, many homeowners find that ground source heat pumps are worth considering.
They offer efficient, low‑carbon heating and can provide reliable performance throughout the year. However, the higher installation costs and space requirements mean they are not the right choice for every household.
Whether a system represents good value will depend on your property, energy usage, available grants and long‑term plans for your home.