As concerns about climate change, rising fuel bills, and government ambitions to achieve net-zero emissions by 2050 are on everyone’s minds, an increasing number of UK homes are turning to air-source heat pumps (ASHPs). These energy-efficient solutions offer a cleaner way to warm your home while significantly reducing your carbon footprint.
Suppose you’re considering installing an air-source heat pump system on your property in 2025, but you’re unsure about how to do so. In that case, this guide will take you through everything you need to know—how they work, what you need to do for installation, grants available and professional maintenance advice.
What Is an Air Source Heat Pump and How Does It Work?
An air source heat pump draws heat from outside and uses it to both warm and provide hot water for heating your house or supplying domestic hot water. An air source heat pump (ASHP) functions much like a refrigerator, employing refrigerant cycles and compressors to transfer heat, working in reverse to refrigeration cycles. Ashps come in two primary forms.
- Air-to-water systems: These heaters utilise airflow to heat water, which is then dispersed through radiators or underfloor heating systems. This is the most common in the UK.
- Air-to-air systems: Warmth is introduced to rooms through air-to-air systems, which are commonly found in hybrid or smaller dwellings.
Advantages:
- Up to 300% efficiency
- Low carbon output
- Government grant-eligible
- Operating even in chilly UK weather
Families can save a significant amount of money by installing air-source heat pumps to upgrade their existing electric heating systems, oil heating systems, or LPG heating systems.
When fitting an air source heat pump, what are my choices?
When selecting an air source heat pump, there are two alternatives:
1. Monobloc System
With a single external compact unit, a monobloc system takes up less internal space and can be fitted rapidly, making it ideal for small dwellings and retrofits.
2. Split System
It has increased control and efficiency in energy usage. They are suitable for homes located in colder climates or those with higher heating needs.
The choice should be made depending on your property size, insulation levels, and heating requirements.
Does Your Property Satisfy The Heat Pump Insulation Requirements?
Before installing, your property must meet specific criteria in terms of energy efficiency:
- Proper insulation: Solid insulation, such as cavity wall, loft, and floor insulation, plays a crucial part.
- Location for an outdoor unit: Ensure it is placed in a well-ventilated area, typically at the rear or side of your building.
- Internal space for hot water cylinder: Needed for air-to-water systems.
- Radiators or underfloor heating: It needs to be upgraded to distribute low-temperature heat efficiently.
- EPC Rating: An EPC rating of or better is typically required for grants.
An experienced installer should conduct an on-site survey to assess suitability and provide any necessary recommendations.
Step-by-Step Guide: How to Install an Air Source Heat Pump
Step 1: Initial Consultation and Research
To make the best choice of system and installer, gather quotes from MCS-approved installers, such as btsgrants.uk (reliable firms typically offer free home visits), before beginning research on potential systems.
Step 2: Home Survey and Heat Loss Calculation
One of your installers will visit to examine the existing heating system, conduct heat loss measurements, assess insulation levels, and determine the ideal location for the unit’s installation.
Step 3: System Design and Planning
Customised systems are created according to your specific heat load and application, taking into account various considerations such as:
- Pump sizing
- Cylinder specifications
- Planning for pipework and layout
Step 4: Installation
This stage typically takes between 2 and 4 days and involves:
- Mounting the outdoor unit on a concrete base or wall brackets.
- Installation of interior components, including the hot water cylinder and controller.
- Link your system with radiators or underfloor heating systems.
- Pipe testing and sealing.
Step 5: Commissioning and Transfer
- Once complete, testing and commissioning of the system begin.
- Installers will explain how to operate it.
- Your warranty documentation, servicing schedule and any applicable grant paperwork will be provided to you.
Costs and Government Assistance
Estimated Installation Costs and Assistance
- The estimated cost for installing an air source heat pump in small houses varies between £10,000 and £14,000.
- Homes or complex systems requiring larger investments may incur higher charges, with costs estimated to be between £15,000 and over £20,000 for the installation of solar PV systems.
Grants Available in 2025
1. Through the Boiler Upgrade Scheme, you will be able to get:
- £7,500 grant toward the cost of installing an ASHP
- No repayments needed
- Available to homeowners and landlords throughout England and Wales
Your installer can claim the grant on your behalf, significantly lowering upfront costs and making ASHPs more cost-effective than ever.
2. ECO4 Scheme
The ECO4 (Energy Company Obligation) scheme is another significant government-funded initiative that will continue until 2026. It is designed to help low-income and disadvantaged households make their homes more energy efficient.
You might be eligible for a free or significantly subsidised air source heat pump under ECO4 if you:
- Get specific government benefits related to your income (e.g., Pension Credit, Universal Credit)
- Have a poorly energy-efficient home (EPC rating D or lower)
- Are a homeowner or private tenant (with landlord’s permission)
- The scheme can also include upgrades to insulation and other measures to enhance the heating of your property, maximising the benefits of the pump.
It is possible to combine these schemes where possible to make heat pumps extremely affordable—and, in certain instances, basically free. Always check your eligibility with an approved installer or certified ECO4 provider.
What to Expect After Installation
After installation, the system operates quietly in the background, heating your home without requiring you to monitor its operation. You will notice:
- Over time (particularly in off-grid homes), energy bills will decrease significantly.
- Consistent indoor temperatures
- Smart thermostat options for better control
Make sure to:
- Plan annual maintenance
- Perform periodic inspections on both filters and outdoor units during the months of use, especially for filters used with outdoor units.
- Monitor your system using an app or control panel.
Proper Care for Heat Pumps
Regular heat pump maintenance will enable its maximum long-term efficiency, maximise energy savings, and prolong its lifespan.
An Annual Service That Involves:
- Refrigerant level inspection
- Electrical connection inspection
- Cleaning coils and filters
- System pressure and output monitoring
Tips for Homeowners:
- Ensure the outdoor unit remains clear by clearing away leaves, snow or any other obstacles from it.
- Maintain consistent temperatures (frequent changes reduce efficiency)
- Use programmable controls to accommodate your schedule.
An ASHP in good condition can last 15–20 years, which is usually longer than a gas boiler.
Common Challenges and Expert Solutions
Noise Concerns
Contemporary ASHPs are very quiet (40–60 dB). Proper positioning—away from windows or adjacent homes—prevents problems throughout the site.
Cold Weather Efficiency
ASHPs are designed to operate in temperatures as low as -15°C, although efficiency decreases slightly; an appropriately sized system guards against performance problems.
Radiator Compatibility
As heat pumps produce lower temperatures than gas boilers, you may need to install larger radiators or underfloor heating for optimal performance.
Conclusion: Making the Switch to an Air Source Heat Pump in 2025
With Britain working toward a low-carbon future, now is an opportune moment to invest in an air-source heat pump. Thanks to the generous government support, such as the £7,500 Boiler Upgrade Scheme, heat pumps are no longer just environmentally friendly; they are also smart financial decisions.
Whether you’re upgrading an older heating system or considering a more energy-efficient home renovation, a professionally installed air source heat pump can bring year-round comfort, lower running costs, and peace of mind for years.
By taking the necessary steps, such as conducting an accurate home evaluation and selecting certified installers, you can secure your future and contribute to creating a more eco-friendly home environment.
FAQ’S
Typically, two to four days, depending on the complexity and current heating infrastructure.
Typically, no, except if your property is in a conservation area or the unit violates allowed development regulations. Always check with your local planning department for the most up-to-date information.
Higher initial costs, but in the long run, you’ll have reduced energy bills and government grants to cover the gap.
Possibly. Heat pumps are most effective with larger radiators or underfloor systems since they produce lower-temperature heat.
It’s not exactly free, but the £7,500 Boiler Upgrade Scheme significantly reduces the installation cost.
