Ground source heat pump costs and savings

A ground source heat pump can cut your carbon emissions significantly. We explain how much a ground source heat pump costs and what to think about if you're considering having one installed. 

The majority of heat pump installations in the UK are air source heat pumps. Ground source heat pumps are usually significantly more expensive, but can be more efficient than air source heat pumps in areas that often get very cold, because the ground temperature is more consistent and warmer than the air temperature in winter.  

Head over to our introduction to heat pumps if you're not sure which type you need, or see our air source heat pump costs and savings guide.

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How much does a ground source heat pump cost?

According to the Energy Saving Trust, buying and installing a ground source heat pump can cost as much as £28,000 if your ground loop is buried in trenches, or £57,000 if you need to dig a borehole. 

The latest statistics from the government's Boiler Upgrade Scheme - which offers grants to support the installation of heat pumps - show that the cost of ground source heat pump installation for homeowners receiving a grant ranged from around £18,500 to £37,500, with the average being around £25,000 to £27,000. That is for installations in England and Wales between May 2022 and June 2024 and does not include the grant payment, so the price paid by homeowners would be up to £7,500 lower.

The payback period (the time it takes for the cost of the system to be recouped in energy savings) will depend on how efficiently your system works, the type of system you're replacing, how well insulated your home is, how efficiently you use the system's controls, and how you'll be using the heat generated from the pump. 

Financial help is available via the government Boiler Upgrade Scheme in England and Wales, or the Home Energy Scotland Grant and Loan. A grant will only pay part of the cost of a ground source heat pump.

Find out more about the Boiler Upgrade Scheme and how to apply.

How to calculate ground source heat pump savings

To get a better idea of how much a ground source heat pump would cost to run, and whether it would be cheaper than your existing heating system, you can make a rough calculation using your own data.

We've worked out an example, below, for a typical household currently using a gas boiler.

Existing heating and hot water costs using gas

Typical household gas consumption is 11,500kWh a year, according to Ofgem's latest calculations for a 'medium' consumption household. Your own figures may be higher or lower than that. 

Gas used for cooking makes up around 2.5% of the total (287.5kWh), so that leaves 11,212.5kWh a year as the typical quantity of gas used for heating and hot water in your home.

From April 2025, the average price cap for gas for price capped direct debit customers is 6.99p per kWh (£0.0699 per kWh). The annual cost of typical gas consumption is 11,212.5 x £0.0699 = £783.75 (rounded to £784).

From April 2025, the average gas standing charge is 32.67p per day (£0.3267 per day) so the annual standing charge cost is 365 (days) x £0.3267 = £119.25 (rounded to £119). 

That makes the total gas bill for heating and hot water (excluding cooking) £903. 

What's your heat demand?

To calculate the cost of running a heat pump, you need to work out your household heat demand using your current annual gas consumption and boiler efficiency.

A new A-rated gas boiler must be a minimum of 92% efficient; however, studies have shown that the actual in-use performance is generally lower. Older boilers are also less efficient, so we've assumed an average of 85% efficiency.

As calculated above, gas consumption for heating/hot water is 11,212.5kWh but, as only 85% of that is being turned into heat, we calculate actual heat demand at 11,212.5 x 0.85 = 9,531kWh.

Potential heating and hot water costs using a heat pump

A typical ground source heat pump can generate 3.5 to 4.5 units of heat for each unit of electricity it uses. We've assumed a COP (Coefficient of Performance) of 4.0 (i.e. 400% efficient) for the following example. 

To deliver the heat demand of 9,531kWh, the amount of electricity required will be 9,531 ÷ 4 = 2,382.75kWh.

From April 2025, the price cap for electricity is 27.03p per kWh, or £0.2703 per kWh. So the annual cost of electricity for heating and hot water is 2,382.75 x £0.2703 = £644.06 (rounded to £644).

We've assumed that all households already pay the standing charge for electricity, so there's no need to add this. It is an average 53.8p a day, or £196 a year. 

Which is cheaper – gas boiler or ground source heat pump?

In this example, the ground source heat pump is cheaper to run, saving £259 a year on average. 

If your gas boiler is less efficient, or you install a more efficient heat pump, then you will see greater cost savings by switching to a heat pump. 

Changes in energy prices will affect future comparisons. If the unit price of gas rises more quickly than the unit price of electricity, then the cost benefit of a heat pump will be greater. 

Calculate your own savings

To  calculate how much your own home might cost to heat with a heat pump or a gas or oil boiler, you can use the following formula:

(heat demand / heating efficiency) x fuel price [+ annual standing charge] = annual heating cost

Heat demand: You can find your fuel consumption (in kWh) on your energy bills. If you use gas for cooking, deduct around 2.5% to calculate how much is used for heating and hot water. Then divide this by the heating efficiency (if your boiler is 85% efficient, divide by 0.85). This is your annual heat demand (for heating and hot water in your home).

Heating efficiency: If you know your boiler's efficiency, you can use that figure. If you know the make and model, you can check the efficiency in the product characteristics database. New gas boilers must be at least 92% efficient, but an older one may be much less efficient. Boilers often run less efficiently than rated, as our boiler efficiency guide explains.

The efficiency of a ground source heat pump is typically between 3.5 and 4.5. If you're thinking of installing a specific model, you can find the COP in the manufacturer's product specification, but your installer should let you know what efficiency range to expect. 

What other costs are involved in buying a ground source heat pump?

If you plan to replace your gas boiler with a ground source heat pump, you may also consider swapping your gas cooker for an electric one. Retaining a gas supply just for cooking will mean the standing charge is disproportionately high. 

If you terminate your gas supply, you may have to pay for removal of the meter. The cost varies according to supplier. If you don't remove the meter, you must continue to pay a standing charge.

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Is your home suitable? 

The heat produced by a ground source heat pump is at a lower temperature than other forms of heating. Ground source heat pumps work best with underfloor heating, which requires lower flow temperatures than radiators. 

Our underfloor heating guide can help you to decide if it's right for your home.

Ground source heat pumps are generally better suited to new-build properties than retrofitting to an existing home. This is because costs could be reduced if the heat pump and an appropriate heating system are included as part of the building's specification, rather than having to retrofit later on. 

If you want to retrofit an existing home with a ground source heat pump, you may be able to get a grant to help pay some of the cost of replacing an old heating system.

A well-insulated house is essential to making the most of the heat generated by your ground source heat pump. Otherwise the heat escapes more easily.

Even if you have a gas boiler, insulation is crucial for making sure you're not paying for heat that is simply escaping. Head to our insulation advice guides to find out more.

Running costs can be higher if you're also using the system for your hot-water supply, and you may require a supplementary electric immersion heater to keep up with your heating needs. Find out more in our dedicated guide to electric immersion heaters.

The ground loop element should need little maintenance once it's in place. They usually come with warranties of two or three years, but should operate for 20 years or more.

Whether or not you decide to get a ground source heat pump, it's worth making sure you're on the best energy deal for you. Use our energy switching service to compare gas and electricity prices.

Getting your ground source heat pump through a manufacturer

While energy companies like British Gas, EDF, E.ON and Octopus sell air source heat pumps from major brands, they don't sell ground source heat pumps. 

The following companies sell and install ground source heat pumps:

• Kensa 
• Vaillant 
• Viessmann 

Vaillant sells flexoTHERM heat pumps which are ground source but convertible to air or water sources too. 

We recommend seeking advice from an MCS-certified contractor who will assess your home's heating requirements before proposing the most suitable heat pump size and model. They may also be able to apply for a government grant on your behalf.

Getting your ground source heat pump through an independent installer

If you want to find an independent installer to help you scope a ground source heat pump and pick a model, find an MCS certified contractor who will be able to apply for a government grant on your behalf.

Installers certified by MCS agree to follow a code of conduct known as RECC (Renewable Energy Consumer Code). This means they should not use high-pressure selling techniques, nor should any subcontractors they employ. 

This should save you from misleading selling techniques like unrealistically high initial prices with time-limited discounts, a technique which would give a seller leverage to negotiate a bad deal for you.

Other examples of conduct forbidden by RECC includes exaggerating a heat pump's performance or withholding information that might affect your decision to buy one. 

There's a need for more heat pump installers in the UK because it's still a developing market. Compared to installing a boiler, it's labour-intensive work that requires more people and more days for installation.

We recommend seeking a vetted Which? Trusted Trader operating in your area. Otherwise, the MCS database is a good way to find an qualified installer.