14 April 2025
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Martyn Bridges, Director of External Affairs at Worcester Bosch, looks at the benefits and challenges of adopting hybrid heating systems.
The UK faces a significant challenge in its quest to achieve net zero emissions, with home heating at the heart of the issue. Currently, most homes rely on gas or oil-fired boilers, while only around 1% of homes have made the switch to heat pumps. Though transitioning to heat pumps is increasingly feasible, adoption rates remain frustratingly below Government targets of 600,000 annual installations. For millions of households, hybrid heating systems could provide a practical and accessible solution, bridging the gap between traditional boilers and low-carbon alternatives. Let’s explore:
What are hybrid systems
Hybrid heating systems combine a boiler and an air or ground to water heat pump. This combination allows homes to benefit from the efficiency and sustainability of heat pumps without the need to entirely replace existing heating infrastructure. Within a typical hybrid setup, the heat pump handles the majority of the heating load (up to around 80%), while the boiler is used for specific tasks such as providing hot water or operating during extremely cold weather. For example, in Scotland’s recent sub-zero temperatures of -12°C, the boiler would provide additional heating capacity to ensure comfort.
Hybrid systems are particularly suited to the UK housing stock. Many homes, particularly those built within the last thirty years, have radiators and microbore pipes designed for high temperature water from boilers. These features can make transitioning to low temperature heat pumps disruptive and expensive. By integrating a heat pump with an existing or new boiler, hybrid systems overcome many of these barriers while retaining the familiarity of traditional heating setups.
The benefits of hybrids for consumers
For homeowners, hybrid systems offer several practical advantages:
- Minimal disruption: Unlike fully switching to a heat pump, installing a hybrid system doesn’t require significant changes to existing heating infrastructure. There’s normally no need to resize radiators or try and find a location for a hot water storage cylinder, making the installation process quicker and less costly.
- Familiar operation: One of the main challenges of heat pump systems is the need to adjust to constant low temperature heating. Hybrids, on the other hand, allow customers to continue using their heating systems in much the same way they do now. This reduces the behavioural shift that may otherwise be required, making hybrid systems a more appealing option for many.
- Efficiency and cost savings: Hybrids prioritise the use of the heat pump, with a controller determining the most efficient energy source based on factors like outdoor temperature, energy costs, and grid demand. This optimisation enables reduced carbon emissions while keeping running costs competitive.
- Flexibility during extreme weather: For colder climates or during harsher winters, hybrid systems provide additional peace of mind. When the heat pump alone cannot meet the demand, the boiler seamlessly supplements the system to maintain consistent warmth.
Hybrids role in the path to net zero
The UK Government has ambitious net zero targets, and decarbonising home heating is critical to achieving them. While fully renewable solutions like heat pumps offer the highest level of carbon reduction, hybrid systems provide a more practical and scalable approach in the short to medium term for many. A hybrid system can reduce a home’s carbon emissions by up to 80%, a significant improvement compared to traditional boilers. The reduction is crucial for households that are not yet ready for or able to adopt fully renewable solutions. Moreover, hybrids alleviate stress on the electrical grid. Heat pumps rely on electricity, which is already under increasing demand as the UK transitions to renewable energy sources. Hybrids mitigate this by using gas or oil during peak demand, ensuring a stable and reliable energy supply.
Challenges to adoption
Despite their advantages, hybrid systems remain underutilised in the UK compared to other European countries, where they are often the first choice for heating upgrades. A major reason for this disparity is the lack of financial incentives.
In Europe, many Governments provide subsidies for hybrid systems, making them more accessible to homeowners. In the UK however, the Boiler Upgrade Scheme (BUS) only supports full heat pump installations, leaving hybrids without comparable f inancial backing. Until recently, there was also no way to register hybrid installations with the Microgeneration Certification Scheme (MCS), a requirement for renewable energy initiatives. This has now changed and the Government is reportedly considering support for hybrids in their 2025 review of the BUS. Another barrier is the current cost imbalance between gas and electricity. Electricity is approximately four times more expensive than gas in the UK, making the running cost of hybrid and heat pump systems less appealing to consumers. Rebalancing energy prices and introducing additional incentives, such as council tax reductions for greener homes, could help drive adoption.
The potential of hybrids
Hybrid systems are not just a stopgap solution; they represent a forward-thinking approach to balancing environmental goals with practical realities. By reducing emissions significantly while utilising existing infrastructure, they offer an accessible way for millions of UK households to contribute to the country’s decarbonisation efforts. Policymakers have a critical role to play in unlocking the potential of hybrid systems. Providing financial support for hybrids, addressing the energy price disparities, and increasing public awareness of their benefits could accelerate adoption and make a meaningful impact on the UK’s net zero strategy. For homeowners, hybrids offer the opportunity to embrace greener technology without the need for disruptive change or drastic shifts in heating habits. They combine the best aspects of traditional boilers and heat pumps, providing comfort, efficiency, and flexibility in one package.
Going forward
As the UK strives to achieve its net zero targets, hybrids present a compelling solution. By combining the efficiency of heat pumps with the familiarity of traditional boilers, hybrids provide a practical and scalable solution to reducing carbon emissions across millions of homes. While challenges such as financial incentives and energy costs need to be addressed, the potential of hybrids makes them an important transitional technology. With the right support from policymakers and increased awareness among consumers, hybrid systems could have a crucial role in the future of home heating, helping the UK move closer to its goal of a greener and more sustainable future.
