A ground source heat pump, also known as a ground-to-water heat pump or geothermal heat pump, uses captured heat from the ground outside to heat your central heating system and heat the water in a hot water cylinder feeding to all of your hot taps and showers.

A ground source heat pump is made up of a loop of buried pipework that circulates a mixture of water and antifreeze fluid which flows around the ground loop pipe buried in trenches.

Heat from the ground is absorbed into the fluid (thermal transfer fluid -TTF), which then passes through a heat exchanger into the heat pump. This raises the temperature of the fluid and then transfers that heat to water in your central heating, warming your radiators or the water for your hot taps.

Ground source heat pumps are low-maintenance that can provide cooling in summer as well as heating in winter, but they are more expensive than investing in an air source heat pump.

Are ground source heat pumps a good idea?

Less than half of UK homes are suitable to have a ground source heat pump installed. If your property benefits from garden space, then government offers include financial aid (The Renewable Heat Incentive (RHI) scheme) to help with the expensive upfront cost of installing a ground source heat pump. Having one installed will save overall on your energy bills, helping to recover the upfront costs of the installation. The Energy Savings Trust estimates that a ground source heat pump could save you up to £1,400 a year.

For every unit of electricity used by a heat pump, three to four units of heat are captured and transferred to your home. This means that ground source heat pumps are 300 to 400% efficient in terms of its use of electricity.

They let off 70% less carbon dioxide emissions compared to traditional gas boiler systems. If the electricity used to power the pump is provided by renewable energy, carbon emissions can be reduced to zero.

Heat pump systems are safer than gas-fired or oil-fired boilers as they rely on electricity rather than generating heat by burning fuel.

They have less on-going maintenance as there is no need for an annual check as they don’t pose the risk of a carbon monoxide leak. With less need for maintenance comes a longer life span because the ground heat exchanger element of the heat pump installation has a design life of over 100 years.

How much space do I need to install a ground source heat pump?

Mid-terraced homes and blocks of flats are not suitable for a geothermal heat pump as they need outdoor space around your home to be installed. Unless there is a communal piece of garden and the expense agreed to be shared. The heat pump does not need a large garden, but space close by for the trenches and boreholes to be dug. A ground source heat pump needs more space than an air source heat pump. An average horizontal system needs approximately 700 square metres, whereas a vertical borehole system needs enough outside space for the drilling rig to access the site, but boreholes are only approximately 20 centimetres wide.

Installing the ground loop will need earth that is suitable for digging and able to have the necessary machinery to access. The space must be clear from trees because roots will be an issue when creating the trenches. The length of the ground loop and trenches depend on the size of your home and the amount of heat you need.

For a small garden space, boreholes can be drilled vertical to gather the heat. Although, this can be more costly than digging trenches as drilling down will need a specialist ground survey. Larger houses may need multiple boreholes, which must be placed 5-6 metres apart. Borehole depth depends on the heat demand of a property and the underlying geology but is likely to be around 75-200 metres deep.

Inside the home will need space for the indoor heat pump unit, which contains key components. The inside unit will also house the hot water cylinder.

How much will it cost to install a ground source heat pump?

Installing a ground source heat pump is a very costly upfront expense. This can range between £13,000 and £45,000 depending on the type and size of the system. The time installing the heat pump can take up to a week's worth of labour and you may need a landscaper as well as a gas engineer. The installation is dependent on the layout of your garden and access to the ground. If you have the space, trenches will be cheaper than a borehole to lay the ground loop. 

Trenches only need to be dug up to two metres deep, keeping costs anywhere from £13,000- £35,000.

A borehole has to be dug up to a hundred metres deep, resulting in an expense of £30,000 - £45,000.

The brand, model and size of the geothermal heat pump will greatly affect the overall cost as well as the size of the house as this depends on how much heat will be needed from the unit. A new build will be easier to fit a ground source heat pump as there is not yet an established garden and during the building work phase, it should be easier to get the digger into the garden to prepare trenches or boreholes.

Installing a ground source heat pump system involves work on the outside of the house and the inside;

Outside house preparation

  • hiring a digger machine
  • hiring a person to control the digger
  • digging the trenches
  • laying the coils of pipework
    (If not enough space for trenches then two or three vertical boreholes to be dug)

Inside house preparation

  • installing the heat pump
  • this may include a hot water cylinder
    or may be a small pump fitted in a kitchen cupboard

Heat pumps are also generally installed close to an external wall to give easy access to the ground array pipes but with an electrical power output to run the pump.

Cost to install a ground source heat pump

Per

Average total labour cost

Digging trenches for an 11kw heat pump

Per day

£3750

Creating boreholes for an 11kw heat pump

Per day

£9750

Installing the ground source heat pump inside the house

Per day

£300

Installing the pipe work in the trenches

Per day

£520

How long do ground source heat pumps last?

Ground source heat pumps are long lasting. People can generally get 20-25 years lifespan out of a unit with some lasting as long as 50 years. The pumps are designed well and there is not much that can go wrong with the pump. Of course, longevity will vary depending on model and manufacturer.

Gas boilers tend to need replacing every 12 years or so. So the fact that the heat pump can double that lifespan, coupled with the RHI scheme, makes embarking on such a costly expense more worthwhile.

Usually, the component to break first is the compressor. This is a part that is constantly in use so it tends to burn out and can be replaced without needing to replace the entire ground source heat pump.

Common issues with a ground source heat pump

Before calling out a professional gas engineer, some troubleshooting to do first to diagnose the issue, would be to check that;

  • power is communicating to the unit and no tripped circuit breakers
  • air filters and coils are clean or replaced if dirty
  • the loop pumps are running
  • the thermostat is at an appropriate temperature
  • heat pump is correctly set to heating or cooling
  • there are no signs of leaks or broken wiring 
  • water is properly circulating through the heat exchanger
  • the pressure inside of the loop system is correct

Common issues with ground source heat pump include;

A decrease in heating or cooling levels
This might be caused by restricted air flow, especially if the air filters appear dirty, replace them to solve the issue.

Cooling function not working
Perhaps a low refrigerant charge which could be caused by the heat exchanger clogged with limescale or a faulty reversing valve. Possible fix might be as simple as repositioning the thermostat for a better and more accurate reading. 

High amounts of indoor humidity
Too much airflow or a unit that is too big for your home. Adjusting the fan motor speed may fix this problem.

Air Temperature too cool
Perhaps from too much airflow and the fan speed needs adjusting.


Estimates for common heating engineer jobs;

Job Estimate
Cost to replace a hot water immersion heater £275
Cost to fit underfloor heating £250
Cost to replace a vented hot water cylinder £330
Cost to replace a heating programmer £180
Cost to powerflush a central heating system £500 Visit
New combi or system boiler installation – like for like replacement £500
Cost to install a ground source heat pump £3750
Cost to fix a boiler fault error code £85
Cost to replace an unvented hot water cylinder, e.g., Megaflo £305
Cost to fit thermostatic radiator valves (TRVs) £94
Cost to fit smart heating controls £100
Cost to fit a radiator £80
Boiler service cost £90
Boiler repair costs (e.g. pump, diverter valve or heat exchanger) £333
Cost to install an air source heat pump £556
Replacement of a vented system £580

Rates for other trades

Install a ground source heat pump cost in the UK
Install a ground source heat pump cost in the UK (excluding VAT or callout charges)
Location in UKInstall a ground source heat pump cost
Install a ground source heat pump near Aberdeen£4200
Install a ground source heat pump near Amber Valley£3600
Install a ground source heat pump near Angus£4050
Install a ground source heat pump near Arun£4095
Install a ground source heat pump near Ashfield£3570
Install a ground source heat pump near Aylesbury Vale£4215
Install a ground source heat pump near Barnsley£3495
Install a ground source heat pump near Basildon£3960
Install a ground source heat pump near Basingstoke & Deane£4095
Install a ground source heat pump near Bassetlaw£3675
Install a ground source heat pump near Bath & North East Somerset£3900
Install a ground source heat pump near Bedford£4200
Install a ground source heat pump near Belfast£3180
Install a ground source heat pump near Birmingham£3480
Install a ground source heat pump near Blackburn£3555
Install a ground source heat pump near Blackpool£3645
Install a ground source heat pump near Bolton£3720
Install a ground source heat pump near Bournemouth£4065
Install a ground source heat pump near Bracknell Forest£4305
Install a ground source heat pump near Bradford£3510
Install a ground source heat pump near Braintree£3870
Install a ground source heat pump near Breckland£3630
Install a ground source heat pump near Bridgend£3390
Install a ground source heat pump near Brighton£3960
Install a ground source heat pump near Bristol£3795
Install a ground source heat pump near Broadland£4005
Install a ground source heat pump near Broxtowe£3555
Install a ground source heat pump near Bury£3675
Install a ground source heat pump near Caerphilly£3390
Install a ground source heat pump near Calderdale£3450
Install a ground source heat pump near Cambridge£4125
Install a ground source heat pump near Canterbury£3675
Install a ground source heat pump near Cardiff£3480
Install a ground source heat pump near Carmarthenshire£2985
Install a ground source heat pump near Charnwood£3450
Install a ground source heat pump near Chelmsford£3885
Install a ground source heat pump near Cheltenham£4650
Install a ground source heat pump near Cherwell£4155
Install a ground source heat pump near Chester£3285
Install a ground source heat pump near Colchester£3825
Install a ground source heat pump near Conway£3060
Install a ground source heat pump near Coventry£3495
Install a ground source heat pump near Crewe & Nantwich£3510
Install a ground source heat pump near Dacorum£4200
Install a ground source heat pump near Derby£3450
Install a ground source heat pump near Doncaster£3660
Install a ground source heat pump near Dover£3510
Install a ground source heat pump near Dudley£3495
Install a ground source heat pump near Dumfries & Galloway£3780
Install a ground source heat pump near Dundee£4110
Install a ground source heat pump near East Ayrshire£2850
Install a ground source heat pump near East Devon£3705
Install a ground source heat pump near East Dunbartonshire£4260
Install a ground source heat pump near East Hampshire£4035
Install a ground source heat pump near East Hertfordshire£4155
Install a ground source heat pump near East Lindsey£3285
Install a ground source heat pump near East Riding£2940
Install a ground source heat pump near Eastleigh£4200
Install a ground source heat pump near Edinburgh£3840
Install a ground source heat pump near Elmbridge£4380
Install a ground source heat pump near Epping Forest£4395
Install a ground source heat pump near Erewash£3495
Install a ground source heat pump near Exeter£3855
Install a ground source heat pump near Falkirk£4125
Install a ground source heat pump near Fife£3915
Install a ground source heat pump near Flintshire£3390
Install a ground source heat pump near Gateshead£3900
Install a ground source heat pump near Gedling£3525
Install a ground source heat pump near Glasgow£4185
Install a ground source heat pump near Gloucester£4830
Install a ground source heat pump near Guildford£4440
Install a ground source heat pump near Gwynedd£3480
Install a ground source heat pump near Halton£3540
Install a ground source heat pump near Harrogate£3360
Install a ground source heat pump near Havant & Waterloo£3990
Install a ground source heat pump near Highland£4800
Install a ground source heat pump near Horsham£4020
Install a ground source heat pump near Huntingdonshire£4065
Install a ground source heat pump near Ipswich£4545
Install a ground source heat pump near Isle of Wight£3930
Install a ground source heat pump near Kings Lynn & West Norfolk£3900
Install a ground source heat pump near Kingston-upon-Hull£2940
Install a ground source heat pump near Kirklees£3420
Install a ground source heat pump near Knowsley£3480
Install a ground source heat pump near Lancaster£3855
Install a ground source heat pump near Leeds£3405
Install a ground source heat pump near Leicester£3480
Install a ground source heat pump near Lisburn£3165
Install a ground source heat pump near Liverpool£3465
Install a ground source heat pump near London£4335
Install a ground source heat pump near Luton£4305
Install a ground source heat pump near Macclesfield£3630
Install a ground source heat pump near Maidstone£3825
Install a ground source heat pump near Manchester£3585
Install a ground source heat pump near Mid Bedfordshire£4170
Install a ground source heat pump near Mid Sussex£4110
Install a ground source heat pump near Middlesbrough£3660
Install a ground source heat pump near Milton Keynes£4215
Install a ground source heat pump near Neath Port Talbot£3510
Install a ground source heat pump near New Forest£4035
Install a ground source heat pump near Newbury£4110
Install a ground source heat pump near Newcastle-under-Lyme£3345
Install a ground source heat pump near Newcastle-upon-Tyne£3915
Install a ground source heat pump near Newport£3495
Install a ground source heat pump near North Ayrshire£3360
Install a ground source heat pump near North East Lincolnshire£3810
Install a ground source heat pump near North Hertfordshire£4200
Install a ground source heat pump near North Lanarkshire£4200
Install a ground source heat pump near North Lincolnshire£3315
Install a ground source heat pump near North Somerset£3720
Install a ground source heat pump near North Tyneside£3885
Install a ground source heat pump near North Wiltshire£4650
Install a ground source heat pump near Northampton£4080
Install a ground source heat pump near Norwich£3900
Install a ground source heat pump near Nottingham£3450
Install a ground source heat pump near Nuneaton & Bedworth£3450
Install a ground source heat pump near Oldham£3630
Install a ground source heat pump near Oxford£4215
Install a ground source heat pump near Pembrokeshire£3060
Install a ground source heat pump near Perth & Kinross£4050
Install a ground source heat pump near Peterborough£4110
Install a ground source heat pump near Plymouth£3690
Install a ground source heat pump near Poole£4050
Install a ground source heat pump near Portsmouth£3945
Install a ground source heat pump near Powys£4620
Install a ground source heat pump near Preston£3690
Install a ground source heat pump near Reading£4320
Install a ground source heat pump near Redcar & Cleveland£3525
Install a ground source heat pump near Reigate & Banstead£4365
Install a ground source heat pump near Renfrewshire£4005
Install a ground source heat pump near Rhondda, Cynon, Taff£3225
Install a ground source heat pump near Rochdale£3630
Install a ground source heat pump near Rochester-upon-Medway£4200
Install a ground source heat pump near Rotherham£3555
Install a ground source heat pump near Salford£3585
Install a ground source heat pump near Salisbury£3765
Install a ground source heat pump near Sandwell£3465
Install a ground source heat pump near Scarborough£3630
Install a ground source heat pump near Scottish Borders£5550
Install a ground source heat pump near Sefton£3465
Install a ground source heat pump near Sevenoaks£4005
Install a ground source heat pump near Sheffield£3630
Install a ground source heat pump near Slough£4335
Install a ground source heat pump near Solihull£3480
Install a ground source heat pump near South Ayrshire£3405
Install a ground source heat pump near South Bedfordshire£4200
Install a ground source heat pump near South Cambridgeshire£3975
Install a ground source heat pump near South Gloucestershire£3855
Install a ground source heat pump near South Kesteven£4080
Install a ground source heat pump near South Lanarkshire£4140
Install a ground source heat pump near South Oxfordshire£4110
Install a ground source heat pump near South Somerset£3945
Install a ground source heat pump near South Tyneside£3885
Install a ground source heat pump near Southampton£4155
Install a ground source heat pump near Southend-on-Sea£3825
Install a ground source heat pump near St Albans£4350
Install a ground source heat pump near St Helens£3465
Install a ground source heat pump near Stafford£3540
Install a ground source heat pump near Stockport£3615
Install a ground source heat pump near Stockton-on-Tees£3690
Install a ground source heat pump near Stoke-on-Trent£3345
Install a ground source heat pump near Stratford-on-Avon£3690
Install a ground source heat pump near Stroud£4320
Install a ground source heat pump near Suffolk Coastal£4800
Install a ground source heat pump near Sunderland£3885
Install a ground source heat pump near Swale£3780
Install a ground source heat pump near Swansea£3420
Install a ground source heat pump near Tameside£3570
Install a ground source heat pump near Teignbridge£3780
Install a ground source heat pump near Tendring£4305
Install a ground source heat pump near Test Valley£3915
Install a ground source heat pump near Thamesdown£4650
Install a ground source heat pump near Thanet£3825
Install a ground source heat pump near The Wrekin£3810
Install a ground source heat pump near Thurrock£3975
Install a ground source heat pump near Torbay£3750
Install a ground source heat pump near Trafford£3630
Install a ground source heat pump near Vale of Glamorgan£3450
Install a ground source heat pump near Vale of White Horse£4275
Install a ground source heat pump near Vale Royal£3360
Install a ground source heat pump near Wakefield£3495
Install a ground source heat pump near Walsall£3465
Install a ground source heat pump near Warrington£3675
Install a ground source heat pump near Warwick£3570
Install a ground source heat pump near Waveney£3795
Install a ground source heat pump near Waverley£4275
Install a ground source heat pump near Wealden£4050
Install a ground source heat pump near West Lancashire£3525
Install a ground source heat pump near West Lothian£4125
Install a ground source heat pump near West Wiltshire£4650
Install a ground source heat pump near Wigan£3555
Install a ground source heat pump near Windsor & Maidenhead£4320
Install a ground source heat pump near Wirral£3420
Install a ground source heat pump near Wokingham£4335
Install a ground source heat pump near Wolverhampton£3480
Install a ground source heat pump near Wrexham Maelor£4245
Install a ground source heat pump near Wychavon£3975
Install a ground source heat pump near Wycombe£4410
Install a ground source heat pump near York£3420