As the UK seeks to achieve carbon-neutral goals by 2050, home heating solutions are rapidly evolving. Two primary contenders for the future of home heating are heat pumps and gas boilers. Understanding the differences between these two systems is crucial for homeowners who want to make informed decisions about energy efficiency, environmental impact, and long-term savings.
This article explores how heat pumps and gas boilers compare in terms of installation complexity, upfront costs, running costs, efficiency, performance, carbon footprint, and suitability for UK homes. It also addresses the future of these heating solutions as the UK prepares for potential regulatory changes.
Table of Contents
What is a Heat Pump?
A heat pump is a device that extracts heat from one source (such as the air, ground, or water) and transfers it to another location, such as inside a home. Despite the name, heat pumps don’t generate heat in the traditional sense. Instead, they move heat from outside to inside, providing both central heating and hot water.
There are several types of heat pumps:
- Air Source Heat Pumps (ASHPs): These extract heat from the air outside and are the most common type of heat pump for residential properties.
- Ground Source Heat Pumps (GSHPs): These work by extracting heat from the ground using a system of pipes buried underground.
- Hybrid Heat Pumps: These combine a heat pump with a traditional gas boiler, switching between the two depending on demand and external temperatures.
- Water Source Heat Pumps: These use water from a nearby water source (like a lake or river) to extract heat.
Heat pumps are generally powered by electricity, which can be a significant consideration given the rising cost of electricity compared to gas. However, heat pumps are highly efficient, and they can provide substantial energy savings if installed in a well-insulated home.
Gas Boilers vs Heat Pumps: The Key Differences
Gas Boilers have long been the staple for home heating in the UK. They are efficient, quick to install, and relatively affordable in terms of initial investment. However, they rely on fossil fuels, contributing to carbon emissions. As a result, they are under increasing pressure due to government climate targets.
Heat Pumps, on the other hand, offer a low-carbon alternative, as they use renewable energy from the air or ground. However, heat pumps come with their own challenges, including higher installation costs and lower heating outputs compared to gas boilers.
Installation Complexity
- Gas Boiler Installation: Installing a gas boiler is a straightforward process. Gas Safe engineers can typically complete the installation within 24 hours, and replacement is often simpler than installing a new system from scratch. If you are replacing an old gas boiler, the process is seamless and doesn’t usually require significant changes to the property.
- Heat Pump Installation: The installation of heat pumps is more complex. For air-source heat pumps, installation can take between 2 to 3 days, depending on the size of the system and the specifics of the property. Ground-source heat pumps require excavation and can take several weeks to install, adding significant complexity and cost.
Moreover, the availability of qualified installers for heat pumps is limited, and as demand grows, waiting times can increase. Due to these complexities, heat pumps tend to be more expensive to install, especially when compared to gas boilers.
Upfront Costs
- Gas Boilers: The installation of a gas boiler is generally more affordable. Gas boiler prices typically range from £1,700 to £3,500, depending on the model, size, and brand. Installation is also relatively cost-effective, making gas boilers a budget-friendly option for most homeowners.
- Heat Pumps: Heat pumps, particularly air-source and ground-source, come with a much higher upfront cost. Air-source heat pumps can cost between £10,000 and £22,000, while ground-source heat pumps can range from £18,000 to £25,000, including installation costs. Although there are government grants available (up to £7,500), the overall cost remains significantly higher than that of a gas boiler. Ground-source heat pumps require additional land excavation, which further drives up the installation price.
Read about: Is a heat pump worth the investment?
Running Costs
- Gas Boilers: Gas is currently cheaper than electricity, making gas boilers a more economical option for heating. On average, a gas boiler requires about 13,600 kWh of energy per year, with costs around 5.48p per kWh. This translates to relatively low running costs, especially for homes with standard insulation and energy efficiency.
- Heat Pumps: Heat pumps are electric-powered and, as such, have higher running costs. With electricity prices being more than three times that of gas, the running costs of heat pumps can be significantly higher, especially in poorly insulated homes. However, heat pumps are extremely efficient, providing 3 to 4 times the heat energy for each unit of electricity consumed. Despite this, in homes with poor thermal efficiency, the operational costs can still exceed those of gas boilers.
For homes with good insulation, heat pumps offer a more cost-efficient solution in the long term. Additionally, households can take advantage of government schemes like the Renewable Heat Incentive (RHI) to offset some of the initial running costs.
Read more: Heat Pump Running Costs in the UK
Efficiency Comparison
- Gas Boilers: Modern A-rated gas boilers are around 90% efficient, meaning they convert 90% of the energy they use into heat, with minimal wastage. This makes them relatively efficient compared to older models, which were less than 70% efficient.
- Heat Pumps: Heat pumps are much more efficient than gas boilers. An air-source heat pump can have an efficiency of 300%, meaning it generates three times more heat than the electricity it uses. Ground-source heat pumps are even more efficient, often reaching efficiencies of over 400%. This makes them far superior in terms of energy usage, but the dependency on electricity and the installation of the right infrastructure can still make them expensive to operate, especially in homes with poor insulation.
Performance & Heat Output Comparison
- Gas Boilers: Gas boilers can generate high heat output very quickly. They are able to deliver a high flow temperature of around 70°C, making them ideal for homes that need rapid and consistent heating. Gas boilers are capable of providing hot water and heating almost instantaneously, which is a significant advantage during cold weather.
- Heat Pumps: Heat pumps operate at much lower temperatures (typically 35°C to 45°C), which means they heat more slowly than gas boilers. As a result, they are more suitable for homes with underfloor heating systems or homes that are well-insulated. For homes with standard radiators, the heat output may be insufficient without upgrading to larger radiators or installing a hot water storage system.
While gas boilers provide immediate and high heat, heat pumps require a longer period to warm up and are less effective in homes that have not been properly insulated.
Read about: Electric Boilers V Gas Boilers
Carbon Footprint Comparison
- Gas Boilers: A modern A-rated gas boiler emits 215 grams of CO2 per kWh of heat delivered. While they are more efficient than older models, they still rely on fossil fuels, contributing to greenhouse gas emissions. Switching from an old non-condensing boiler to a new, more efficient model can save up to 1,220 kg of CO2 per year.
- Heat Pumps: Heat pumps produce zero-carbon emissions during operation, as they do not burn fossil fuels. However, they run on electricity, and the UK’s electricity grid is still largely powered by non-renewable sources. Around 40% of the UK’s electricity comes from renewable sources, making heat pumps a cleaner option compared to gas boilers. While not entirely free of emissions, heat pumps are a significant step toward reducing carbon footprints.
Is My Home Suitable for a Heat Pump?
Before installing a heat pump, it’s essential to consider whether your home is suitable for this type of heating system:
- Insulation Quality: Heat pumps operate most efficiently in homes that are well-insulated. The better the insulation, the less energy is required to heat your home, which can make heat pumps a cost-effective option.
- Existing Heating System: Heat pumps work best with underfloor heating or large radiators designed for low-flow temperatures. If you have a conventional radiator system, you may need to upgrade your radiators to handle the lower temperatures.
- Space Availability: Ground-source heat pumps require significant space for installation, as they require underground piping. Air-source heat pumps also need space to be fitted outside your home.
- Upfront Costs: Heat pumps are an investment, and while grants can help, they still have much higher upfront costs compared to gas boilers. If you are replacing an older system (e.g., electric heating), a heat pump might be a better option.
Read about: Budget-Friendly Air Source Heat Pump Prices & Suppliers
Will Gas Boilers Be Banned?
The UK government has proposed plans to ban gas boilers in new-build homes from 2025, with a complete ban in all properties by 2035. While this won’t immediately affect existing gas boilers, it signals a significant shift towards low-carbon alternatives like heat pumps. Hydrogen boilers, which can utilize the existing gas infrastructure, are also under development, but they remain controversial due to safety concerns.
Conclusion: Which Heating System is Right for You?
Both heat pumps and gas boilers have their strengths and weaknesses. Gas boilers are more affordable, quick to install, and perform well in traditional homes, especially those that are not well-insulated
FAQs
How do heat pumps and gas boilers impact heating costs?
Heat pumps often reduce heating costs in the long term due to higher efficiency, while gas boilers may have lower initial installation costs but higher fuel expenses over time.
Can a heat pump replace a gas boiler in any home?
Yes, but the suitability of a heat pump depends on factors like home insulation, local climate, and existing heating system compatibility. Older homes may require additional insulation for optimal heat pump performance.
What maintenance do heat pumps and gas boilers require?
Heat pumps need regular cleaning of filters and occasional checks on refrigerant levels, while gas boilers require annual servicing to ensure safe and efficient operation.
