A heat pump engineer designs, installs and commissions heat pump systems that transfer heat from the air, ground or water to heat a building. All heat pump installations must be carried out by an MCS certified installer if the installation is to qualify for the Boiler Upgrade Scheme (BUS) grant (currently £7,500 for air source, £7,500 for ground source) and any future government support. Heat pump refrigerant circuits use F-Gas refrigerants, so engineers must also hold F-Gas certification under the F-Gas Regulations. Most heat pump engineers hold City and Guilds 6271 (Air Source Heat Pump Systems) or equivalent, plus F-Gas Category I certification.
What they do
- Carry out a heat loss calculation (BS EN 12831) to size the heat pump correctly
- Design the heat pump system - flow temperatures, emitter sizing and controls
- Install air source heat pump outdoor and indoor units
- Install ground source heat pump ground collectors (trenches or boreholes)
- Connect the heat pump to the existing wet central heating system
- Install or advise on underfloor heating or oversized radiators
- Commission and test the completed heat pump system
- Issue MCS installation certificate and apply for BUS grant on client's behalf
- Service and maintain heat pump systems under annual maintenance agreements
When you need one
A heat pump engineer is needed whenever you want to replace a fossil fuel boiler with a heat pump, or install a heat pump in a new build or extension.
Typical costs (UK, 2025)
| System type | Typical cost (before BUS grant) |
|---|---|
| Air source heat pump (supply + install) | £8,000 - £18,000 |
| Ground source heat pump - horizontal (supply + install) | £15,000 - £25,000 |
| Ground source heat pump - vertical borehole | £20,000 - £35,000 |
| Unvented hot water cylinder (upgrade) | £1,000 - £2,500 |
| Radiator upgrades (per radiator) | £200 - £600 |
| Annual heat pump service | £150 - £350 |
The Boiler Upgrade Scheme (BUS) grant currently provides £7,500 toward air source or ground source heat pump installations - deducted at point of purchase. Costs exclude underfloor heating, which if installed adds £1,500-5,000+ depending on the area covered.
Qualifications to look for
MCS (Microgeneration Certification Scheme) certification is mandatory if you want to access the Boiler Upgrade Scheme grant or any other government heat pump support. Only MCS certified installers can apply for BUS vouchers on behalf of homeowners. Check certification at mcscertified.com.
Heat pumps contain fluorinated greenhouse gases (F-Gases) as refrigerants. The F-Gas Regulations require that engineers who handle, install, service or decommission equipment containing F-Gases hold a valid F-Gas certificate. For heat pump refrigerant work this means City and Guilds F-Gas Category I certification or equivalent. Ask to see the engineer's F-Gas certificate before commissioning any work.
City and Guilds 6271 (Air Source Heat Pump Systems) is the main UK qualification for heat pump engineers. Ground source specialists also require training in ground collector design and installation. A good heat pump installer will also hold a relevant heating qualification (such as Gas Safe registration or Oil Firing Certificate) and be competent in hydraulic system design.
How to find a reputable heat pump engineer
Related Calculators
Extension Cost CalculatorFrequently asked questions
Are heat pumps cheaper to run than a gas boiler?
Whether a heat pump is cheaper to run than a gas boiler depends on your home's insulation, the heat pump's coefficient of performance (COP), and the relative price of electricity and gas. In a well-insulated home a heat pump with a seasonal COP of 3 or above (delivering 3 units of heat for each unit of electricity consumed) can be cheaper to run than a gas boiler when electricity is no more than 3x the price of gas per kWh. As of 2025, electricity costs around 4x the price of gas per unit, so running costs are broadly comparable in a well-insulated property. Heat pumps become more attractive as the electricity price ratio improves, as the grid decarbonises, and in homes where insulation is upgraded.
Do heat pumps work in cold weather?
Yes. Modern air source heat pumps are designed to operate efficiently down to -15 to -20 degrees Celsius and will continue to provide heating at temperatures well below freezing - colder than typical UK winters. Efficiency (COP) does decrease as outside temperature falls, but the best modern units maintain a COP of around 2-2.5 at 0 degrees Celsius. Ground source heat pumps are less affected by outdoor air temperature as they extract heat from the ground, which remains at a relatively stable temperature year round.
Do I need to improve my insulation before installing a heat pump?
Heat pumps work best in well-insulated homes because they deliver heat at a lower flow temperature than a gas boiler (typically 35-45 degrees rather than 70-80 degrees). This means the heating system needs to be sized correctly and the home needs to retain heat effectively. A reputable heat pump installer will carry out a heat loss calculation (to BS EN 12831) before sizing the system. If your home has poor insulation, the installer may recommend improving loft insulation, cavity wall insulation or draught sealing before or alongside the heat pump installation. Underfloor heating or oversized radiators are also typically recommended.