How much does a ground source heat pump cost?

Homeowners are being encouraged to swap gas boilers for greener ground source heat pumps. But it’s a big ask, given the cost...

With autumn fast approaching and sky-rocketing energy costs occupying many of our thoughts, now's the time to consider alternative heating solutions.

Those installing air source heat pumps and ground source heat pumps in their properties are able to secure up to £6,000 to help with the cost under a government scheme launched this year.

But switching from a boiler to a ground source heat pump is a big undertaking, both practically and from a financial point of view.

We take a look at the various costs involved, and whether going eco will really reduce your household bills.

What is the Boiler Upgrade Scheme?

Introduced in April 2020, the Boiler Upgrade Scheme is a government initiative to encourage homeowners to install low-carbon heating systems.

If you want to invest in a ground source heat pump, you'll receive a grant of £6,000 off the cost and installation, while those opting for an air source heat pump will receive £5,000.

All domestic properties and some small non-domestic properties are eligible in England and Wales, however, you can only claim one grant per property. The scheme is due to run until 2025.

What is a ground source heat pump?

Ground source heat pumps take energy from the ground and transfer it into buildings. To do this they access heat from the sun that is stored a couple of metres below the earth’s surface.

As the stored heat is usually at a temperature of only about 10 degrees Celsius, the pumps use electricity to warm it to a higher temperature (about 50 degrees Celsius) suitable to use for a home’s heating and hot water.

There are two types of ground source heat pumps: horizontal pumps and vertical pumps.

Horizontal pumps are cheaper to install but require more outside space. Trenches are dug about two metres below ground and pipes are laid to circulate water, which is then pumped to a heat exchanger.

Vertical pumps work in a similar way but use boreholes dug much deeper into the ground—according to the Ground Source Heat Pump Association, these can be as deep as 150 metres.

Ground source heat pump installation costs

Ground source heat pumps are not cheap. Tradesperson listing site Checkatrade says the average cost ranges from £12,000 to £31,000.

The table below, compiled by Checkatrade, has a breakdown of the average costs.

Item	Range - low	Range - high
Supply and installation of a ground source heat pump	£6,000	£11,000
Horizontal ground loop (space dependent)	£6,000	£12,000
Vertical bore holes	£10,000	£20,000
Upgrade to larger radiators	£1,000	£3,000
Add underfloor heating	£5,000	£15,000
Upgrade cavity wall insulation	£500	£1,000

Whether you choose a horizontal or vertical system, there are a number of other factors that will have an impact on the cost, including the size of your home and its existing heating system.

You may also need to upgrade your home’s radiators or insulation to get the most out of your ground source heat pump, which will add to the cost.

Trenches and pipework for a horizontal heat pump system.
Image: Danielsen_Photography / Shutterstock

Are ground source heat pumps worth it?

There’s no question that ground source heat pumps are more carbon-friendly than traditional alternatives. They typically create three or four units of heat for every unit of electricity used, though exact amounts depend on the specific pump chosen.

When it comes to running costs, the savings are harder to work out. The Ground Source Heat Pump Association estimates running costs could be 30-70% lower, depending on the system you are replacing.

If you are switching from an electric heating and hot water system, a ground source heat pump will certainly save you money on your energy bills. The Energy Saving Trust says those switching from oil or LPG should also see savings.

But the energy-efficiency organisation says those changing from gas boilers are likely to find heat pumps slightly more expensive to run.

Unfortunately, there is also evidence the investment might not stack up when it comes to the value of your property.

A survey of 2,000 people carried out in September 2021 by loan comparison website money.co.uk found that ground source heat pumps were the eco improvement least-valued by potential homebuyers.

It put the average cost of installing a heat pump at £13,000, but the average added value at only £4,041, meaning homeowners installing ground source heat pumps were overall £9,000 worse off in terms of property value.

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Featured image: Studio Harmony / Shutterstock