Ground Source Heat Pumps UK — Costs, Grants, Savings, and How They Work
How ground source heat pumps work in the UK, installation costs, running costs, BUS grant, and whether they're right for your home.
·4 min read
Ground source heat pumps (GSHPs) are one of the most efficient ways to heat a home — extracting heat from the ground to provide heating and hot water. They cost more to install than air source alternatives, but they’re more efficient and quieter.
How Ground Source Heat Pumps Work
Component
What it does
Ground loop
Pipes buried underground that absorb heat from the earth
Heat pump unit
Compresses the absorbed heat to usable temperatures
Distribution system
Underfloor heating or radiators to heat your home
Hot water cylinder
Stores heated water for taps and showers
The ground stays at a relatively constant 10–13°C year-round below a few metres depth, making it a reliable heat source even in winter.
Installer applies directly — you pay the reduced price
Air source grant
£7,500 (same amount since 2024 increase)
Running Costs
Heating system
Annual cost (3-bed detached)
Ground source heat pump
£600 – £1,200
Air source heat pump
£700 – £1,400
Gas boiler
£800 – £1,400
Oil boiler
£1,200 – £2,000
LPG boiler
£1,500 – £2,500
Electric storage heaters
£1,800 – £3,000
Direct electric heating
£2,500 – £4,000+
COP (Coefficient of Performance)
System
Typical COP
What it means
Ground source heat pump
3.5 – 4.5
£1 of electricity produces £3.50–£4.50 of heat
Air source heat pump
2.5 – 3.5
£1 of electricity produces £2.50–£3.50 of heat
Gas boiler
0.9
£1 of gas produces 90p of heat
Direct electric heater
1.0
£1 of electricity produces £1 of heat
GSHPs maintain high efficiency even in cold weather because ground temperature stays constant — unlike air source pumps that lose efficiency when it’s coldest.
Annual Savings
Replacing
Estimated annual saving
Gas boiler
£200 – £600
Oil boiler
£500 – £1,200
LPG boiler
£700 – £1,500
Electric storage heaters
£1,000 – £2,000
Direct electric
£1,500 – £2,500+
Payback Period
Scenario
Upfront (after BUS)
Annual saving
Payback
Replacing gas boiler (horizontal)
£10,000
£400
~25 years
Replacing oil boiler (horizontal)
£10,000
£800
~12 years
Replacing LPG (horizontal)
£10,000
£1,100
~9 years
Replacing electric heating (horizontal)
£10,000
£1,500
~7 years
Payback is fastest when replacing expensive fuels (oil, LPG, electric) and when combined with solar PV.
Is Your Home Suitable?
Requirement
Detail
Outdoor space
Horizontal: garden 2x floor area. Borehole: much less
Insulation
Well-insulated homes benefit most. EPC C or above ideal
Heat distribution
Underfloor heating is best; larger radiators work too
Garden access
Digger access needed for trenching
Ground conditions
Rocky ground is harder/more expensive
Planning permission
Usually permitted development, but check
Best For
Situation
Why
Rural homes off the gas network
Replacing oil/LPG saves most
New builds
Easy to install during construction
Large, well-insulated homes
Maximum efficiency and savings
Homes with space for ground loops
Cheaper horizontal installations
People planning to stay long-term
Payback requires time
Not Ideal For
Situation
Why
Small properties with no garden
Need space for ground loops or boreholes
Poorly insulated homes
Must insulate first — heat pump output is lower temperature
Short-term residents
May not recoup investment
Tight budgets
Significant upfront cost even with grant
GSHP vs ASHP (Air Source)
Feature
Ground source
Air source
Efficiency (COP)
3.5–4.5
2.5–3.5
Winter efficiency
Stays high
Drops in cold weather
Installation cost
£15,000–£35,000
£8,000–£15,000
BUS grant
£7,500
£7,500
Running costs
Lower
Higher
Noise
Silent
Outdoor fan noise
Space needed
Large garden or borehole
Small outdoor unit
Maintenance
Minimal
Minimal
Lifespan
20–25+ years
15–20 years
Visual impact
None (underground)
External unit visible
Maintenance
Task
Frequency
Cost
Annual service
Yearly
£100 – £200
Antifreeze check (ground loops)
Every 5 years
Included in service
System pressure check
Annually
Included in service
Major repair (compressor)
Rare (10-15 years)
£1,000 – £2,500
GSHPs are generally low-maintenance. The ground loops have no moving parts and can last 50+ years.
Summary
Feature
Detail
Installation cost
£15,000 – £35,000
BUS grant
£7,500
Annual running cost
£600 – £1,200
COP efficiency
3.5 – 4.5
Best for
Off-grid homes, replacing oil/LPG, good insulation, space for loops