Ground source heat pumps absorb thermal energy (basically, natural heat) stored in the ground. They then transfer that heat into your underfloor heating, radiators, or hot water cylinder. In other words, they act as a ground source heating system for your home.
Go green with a heat pump
They’re a brilliant low-carbon alternative to traditional heating systems. And with the tech evolving all the time, they’re going to play a massive role in lowering emissions over the next few years.
In this article, we’re going deep on how a ground source heat pump works, the big advantages, and what to consider when it comes to ground source heat pumps’ disadvantages. Let’s drill into it.
How does a ground source heat pump work?
Did you know that the ground just a few metres below the surface stays at a steady temperature all year round – even in the depths of winter?
It’s an incredible, generally untapped resource – and ground source heating systems are here to put all that invisible thermal energy to good use.
Powered by electricity, they use a network of buried pipes to extract low-level heat from a ground water heat pump source. This captured warmth is then passed through the heat pump, where a special fluid absorbs it.
The pump then compresses the fluid, which raises its temperature. This upgraded heat is then transferred into your home, giving you ground source central heating and hot water.
What types of ground source heat pump are there?
There are two kinds of underground heat pump systems: closed-loop and open-loop.
A closed-loop system uses a continuous loop of buried piping filled with fluid. This circulates through the ground, absorbs natural heat and carries it back to the indoor heat pump where the temperature is raised to provide heating and hot water.
An open-loop system takes clean groundwater from a well or borehole and passes it directly through the heat pump. The system captures the water’s heat before returning it to the ground. Open-loop designs can be really efficient. The downside? They rely on a dependable, sustainable water source. It’s exciting to think that what’s beneath our feet could hold the key to warmer homes and a cooler planet!
What are the benefits of a ground source heat pump?
Advantages of ground source heat pumps include:
Lower energy bills: Ground source heat pumps use less energy to deliver the same level of warmth as traditional systems. Savings will depend on what system you’re currently using. But as an example, the Energy Saving Trust estimates that a typical well-insulated detached home could save around £490 a year by switching from an old gas boiler to a ground source air pump.
Use less energy: Again, this comes right back to their incredible efficiency. Ground source heat pumps are serious work horses – for every 1kW of electricity they use, they can generate 3 to 4 kW of renewable heat.
Lower carbon footprint: By tapping into natural underground heat, a ground source heat pump cuts carbon emissions massively. It’s one of the most impactful steps households can take towards a net-zero future. All while keeping comfort levels exactly where you want them: high!
Very little maintenance: Ground source heat pumps have fewer moving parts than combustion-based heating systems (like gas or oil-based boilers) and generally don’t need much servicing. A quick annual check and regular filter cleaning is usually all it takes to keep it ticking over.
What are the disadvantages of a ground source heat pump?
Like any heating system, there are a few practical considerations to keep in mind. Here are some of the typical ground source heating disadvantages that you should be aware of.
Not suitable for all property types: You’ll need enough outdoor space for the underground pipes – or space for a vertical borehole. Even though the pipes are out of sight, they must be installed within your property boundaries, or you’ll need legal permission from the landowner first.
Space requirements for installation: Horizontal ground loops need quite a bit of outdoor space, which can make them more suitable for properties with big gardens or plots of land. Vertical systems take up less surface space but can be more difficult to install.
Better suited to new builds: Ground source heat pumps are often more cost-effective when included as part of a new build project. That said, retrofitting a system can be done but it may involve extra work and higher upfront costs.
Affected by ground conditions: One final thing to consider is that damp clay conducts heat well. But dry, sandy or rocky ground can make your pump a little less efficient. So it’s worth checking what type of soil you have before going ahead to understand how well the system will work.
How much does a ground source heat pump cost?
If your ground loop is buried in trenches, installing a ground source heat pump will cost around £30,000, according to the Energy Saving Trust. But if you’re digging a bore hole it will be more expensive. These are the other key factors that will come into play:
- Heat pump brand, model and size
- Property size (and how much heat it needs)
- Whether it’s a new build or an existing property
- Whether you’re upgrading your radiators or installing new ones/ installing underfloor heating for the first time
Whatever you spend will be an investment on cutting your energy bills in the long run. Check out the table below to see how much you could save in a year.
Is government funding available for ground source heat pumps?
Short answer: yes. With the government’s Boiler Upgrade Scheme, homeowners in England and Wales can get a grant for £7,500 towards a ground source heat pump. To qualify you need to meet the following criteria:
- You own the property you’re applying for (including if it’s a business, a second home, or a property you rent out to tenants)
- You are replacing fossil fuel heating systems like oil, gas, electric or LPG. And if you’ve already had funding to make your property more energy efficient (like insulating it), you should still be eligible for the grant.
Find out how to apply for a heat pump grant here.
Is my home suitable for ground source heat pumps?
Your installer will be able to talk you through everything. But to get you ahead of the curve, think about whether you have enough outdoor space for pipework, what kind of soil you have and whether your house is in a place where you’re able to drill or trench.
The compatibility of your current heating system also matters, and there’s a chance you’ll need to upgrade your radiators or underfloor heating. If space or ground conditions are limited, an air source heat pump could be a better fit.
Are alternative heat pumps available?
Yes – air source heat pumps are a very common alternative. Instead of taking heat out of the ground, they take it from the air outside. They don’t require large trenches or boreholes so they’re usually quicker and easier to install. For more about the different types of heat pump available, our complete guide can help.
On balance, air source systems aren’t quite as efficient but they’re great for properties with limited outdoor space. And just like a ground source geothermal heat pump, they’re much better for the environment and will help lower your energy bills long-term.
Why we focus on air-to-water heat pumps at Hive
You might notice we don’t currently sell ground source heat pumps. That’s because at Hive, we focus on air-to-water systems which are a better fit for most UK homes.
Firstly, they require a much smaller amount of outside space – as long as you can comfortably fit the unit and there’s enough ventilation around it, then that’s all you need. Secondly, they work efficiently in all weather conditions – even when it drops as low as -15°C outside. And they’re also eligible for the Boiler Upgrade Scheme (BUS) grant, which can make installation even more affordable.
So while ground source systems can be great for some spaces, we’ve chosen to specialise in the option that’s more accessible, more versatile, and helps more households move toward low-carbon living.
Looking to install a heat pump?
Great! To get the job done right, you’ll need to find a qualified specialist with a Microgeneration Certification Scheme (MCS) certification. That way you’ll know you’re getting a reliable fitter who can guarantee that everything’s set up safely – and your pump works precisely as it should.
If you’re interested in an air-to-water heat pump, then we can organise the whole thing for you – from first quote to final fitting. We work with three of the UK’s leading installation providers: British Gas, Glow Green and 21 Degrees.
The shift to cleaner heating is happening. Why not get a quote today and make your home part of the story?
FAQs
Do heat pumps need planning permission?
In most cases, you won’t need planning permission to install a heat pump. However, there are a few conditions to be aware of:
- the unit must meet certain noise and size limits
- it should be installed at ground level (normally at the back or side of your home)
- you’re only allowed one unit per property
If your home is listed, or in a conservation area or World Heritage Site, you’ll likely need permission. To stay on the safe side, check with your local planning authority or installer.
Are ground source heat pumps noisy?
No, they’re usually really quiet because the main components (the ground loop and heat exchanger) are buried underground. Inside your home, the heat pump unit makes a low hum, like a modern fridge or gas boiler when it’s running.
Do ground source heat pumps work in cold weather?
Yes. Ground source systems draw from the consistent warmth of the earth, which makes them really reliable even in the chilliest months.
Can a ground source heat pump provide hot water?
Absolutely. The system raises the low-level heat collected from the ground to a higher temperature and this is then stored in a hot water cylinder for showers, baths and everyday use.
Find out more about air source heat pumps
Heat pump systems explained: The complete guide
How exactly do heat pumps work? What do you need to think about before buying one?
Heat pump grants in the UK: Everything you need to know
The government has a range of grants available that make getting a heat pump begin to really make sense, which can provide £7,500 to help with installation.
Heat pumps vs gas boilers: What’s the difference?
Considering switching from a gas boiler to a heat pump? Learn about the differences, benefits and considerations of each option with our guide.