Closed-loop ground source heat pumps
Vertical borehole heat exchangers — the most common and versatile GSHP system type. Suitable for properties of all sizes, including constrained town sites.
How closed-loop systems work
A closed-loop system circulates a mixture of water and antifreeze through sealed pipes (ground loops) installed in vertical boreholes drilled beneath your property. The fluid absorbs heat from the ground as it circulates, and a heat pump concentrates this into usable heating for your building.
Each system is individually designed, taking into account the heat required for the building, the geology on site, available space and the most suitable heat pump. We have been designing and installing closed-loop systems for over 14 years, with more than 450 systems completed.
Our biggest system to date included 50 boreholes at 200m depth each. But the same technology works equally well for a single domestic property — our compact drilling rigs can access gardens through gaps as narrow as 4 feet.
Key specifications
- Borehole depth
- Typically 80m–200m per borehole
- System sizes
- 5kW domestic to 500kW+ commercial
- Pipe type
- HDPE U-loop, fusion welded and pressure tested
- Grout
- Thermally enhanced for maximum heat transfer
- Working fluid
- Water/antifreeze in sealed loop
- Lifespan
- Ground loops 50+ years; heat pump 20-25 years
BUS Grant — up to £7,500
Domestic closed-loop GSHP installations are eligible for the Boiler Upgrade Scheme. As MCS certified installers, we handle all the paperwork.
Suitable for all property types
Country homes
Large properties with gardens — the traditional sweet spot for closed-loop GSHP, often replacing oil boilers.
Town properties
Our compact rigs fit through narrow access. We increasingly install closed-loop systems in central London and other urban sites.
Period buildings
Listed and period properties benefit from the low-temperature output, which works well with underfloor heating and large radiators.
Commercial buildings
Offices, schools, hospitals and multi-unit developments. We design systems from 10kW to 500kW+ with multiple borehole arrays.
Our design approach
This process is one of the most important for your project and is often overlooked by heat pump installers who don't understand the complexities of the geology below your site.
Heat loss assessment
We review the heat loss of your building to determine the required heat pump size and annual run hours.
Geological review
We assess the geology and groundwater saturation beneath your site — this directly impacts how much heat each metre of borehole can deliver.
Collector calculation
We calculate the total metres of ground loop collector required for your geology, then determine the number and depth of boreholes.
Spacing & layout
Borehole proximity is carefully planned to ensure long-term system performance — too close and they interfere with each other over time.
Proposal & estimate
A detailed proposal with technical drawings, calculations and a no-obligation estimate for the complete system.
Installation
Our in-house team handles every aspect: drilling the boreholes, installing HDPE ground loops with fusion welding, pressure testing, thermally enhanced grouting, manifold connections and commissioning.
- ✓Own staff and equipment throughout
- ✓Compact rigs for restricted access
- ✓Cleanest drilling techniques available
- ✓Full pressure testing and certification
- ✓MCS compliant documentation
Maintenance
Each project has a bespoke maintenance programme. Unlike standard heat pump service engineers, we cover all aspects of the installation — from the boreholes themselves through to the plant room and underfloor heating.
- ✓Borehole loop monitoring
- ✓Heat pump servicing
- ✓Plant room checks
- ✓Underfloor heating maintenance
- ✓Annual service agreements available
Interested in a closed-loop GSHP?
Contact us for a no-obligation site assessment and estimate.