Heat Pump vs Gas Boiler: Costs, Running Costs and Which Makes Sense in the UK

For decades, gas boilers have been the standard way of heating homes across the UK. Millions of properties rely on them to provide both heating and hot water. However, as the UK moves toward lower-carbon heating and rising energy costs encourage homeowners to look for more efficient systems, heat pumps are becoming an increasingly popular alternative.

If you’re researching new heating options, one of the most common questions is whether a heat pump or a gas boiler makes more sense for your property.

The answer isn’t always straightforward. Heat pumps operate very differently from traditional boilers, and the right choice often depends on factors such as your home’s insulation, existing heating system, energy prices and long-term plans for the property.

This guide compares heat pumps and gas boilers across the areas that matter most to homeowners: installation cost, running costs, comfort, efficiency and long-term suitability.

If you want to explore the full cost of installing a heat pump first, you may also want to read our guide to heat pump installation costs in the UK as well as the breakdown of heat pump running costs.

Contents

• Heat Pump vs Gas Boiler: Quick Answer
• Upfront Installation Costs
• Running Costs and Energy Efficiency
• Comfort and How Heat Feels in Your Home
• Which Homes Suit Each System
• Future Proofing and Energy Policy
• Heat Pump vs Gas Boiler FAQs

Heat Pump vs Gas Boiler: Quick Answer

In simple terms, gas boilers and heat pumps both provide effective heating for UK homes, but they work in very different ways.

A gas boiler generates heat by burning natural gas. This heat is transferred to water which circulates through radiators and hot water systems throughout the property.

A heat pump works differently. Instead of generating heat directly, it transfers heat from outside air or the ground into the home using electricity. Because of this process, heat pumps can produce multiple units of heat for each unit of electricity used.

Gas boilers typically have lower installation costs and are widely familiar to homeowners and heating engineers. Heat pumps generally involve higher upfront installation costs but can provide higher efficiency and lower carbon emissions over the long term.

Choosing between the two often comes down to the condition of the property, the heating system already installed, and whether the homeowner prioritises lower installation costs or long-term efficiency.

Upfront Installation Costs

One of the biggest differences between gas boilers and heat pumps is the cost of installation.

Gas boilers are usually cheaper to install because the technology is simple, the installation process is well understood, and most homes already have gas infrastructure and compatible heating systems.

Installing a modern gas boiler typically costs between £2,000 and £4,000 depending on the boiler type and complexity of the installation.

Heat pump systems generally cost more because the equipment is more complex and the installation often involves additional work to optimise the heating system.

For example:

• Air source heat pump installations in the UK typically range between £7,000 and £13,000
• Ground source heat pump systems can range between £18,000 and £35,000 depending on ground loop installation

However, government incentives can significantly reduce the cost of installing heat pumps. The Boiler Upgrade Scheme currently offers grants of up to £7,500 towards installation costs for eligible properties.

Once grants are applied, the price difference between heat pumps and traditional boilers can become much smaller than many homeowners expect.

Running Costs and Energy Efficiency

While gas boilers are cheaper to install, heat pumps can offer higher efficiency because of how they produce heat.

Gas boilers typically operate with efficiencies of around 85% to 95%. This means that most of the energy from burning gas is converted into heat, although some energy is always lost through exhaust gases and system inefficiencies.

Heat pumps work differently. Instead of generating heat directly, they transfer heat from the outside environment. Because of this, they can achieve efficiencies of 300% to 400% under the right conditions.

This means that for every unit of electricity used, the system can deliver several units of heat into the home.

Actual running costs depend on several factors including:

• electricity and gas prices
• home insulation levels
• system efficiency
• flow temperature settings
• heating usage patterns

If you want to explore the electricity side of the equation in more detail, our guide to heat pump running costs in the UK explains how efficiency and system settings affect your energy bills.

Comfort and How Heat Feels in Your Home

Although both gas boilers and heat pumps can heat a home effectively, the way they deliver warmth can feel quite different.

Gas boilers typically produce higher-temperature water which heats radiators quickly. Because of this, rooms can warm up rapidly when the heating system turns on. Many homeowners are familiar with this pattern: the heating comes on, the house warms up quickly, and then the system switches off again until the temperature drops.

Heat pumps generally work best using a different approach. Instead of producing bursts of high heat, they are designed to provide steady, lower-temperature heating over longer periods.

This means rooms tend to warm more gradually but remain at a more stable temperature throughout the day. Many households find this creates a more consistent and comfortable indoor environment once the system is properly set up.

Heat pumps also work particularly well with underfloor heating systems, which distribute warmth evenly across large floor areas. Radiators can also be used with heat pumps, although in some cases larger radiators may be needed to provide sufficient heat output at lower temperatures.

The key difference is that heat pumps are usually designed to maintain temperature steadily, while boilers often heat homes in short cycles.

Which Homes Suit Each System?

Whether a heat pump or gas boiler is the better option often depends on the characteristics of the property.

Both systems can work effectively in UK homes, but certain situations tend to favour one over the other.

Homes Well Suited to Heat Pumps

Heat pumps tend to perform best in properties with:

• good insulation levels
• modern heating systems
• underfloor heating or large radiators
• sufficient outdoor space for equipment

New-build homes are often designed with heat pumps in mind because they already meet modern insulation standards and have low heat loss.

However, many existing homes can also operate successfully with heat pumps once insulation and heating systems are optimised.

Homes Well Suited to Gas Boilers

Gas boilers can sometimes remain a practical option for properties where:

• heat loss is relatively high
• insulation upgrades are difficult
• existing radiator systems require very high water temperatures
• space for external equipment is limited

Because boilers produce high-temperature heat, they can deliver strong heating output even in homes with higher heat demand.

This flexibility is one reason gas boilers remain common across the UK housing stock.

Future Proofing and Energy Policy

Energy policy is another factor influencing the heating choices homeowners make today.

The UK government has set targets to reduce carbon emissions from buildings, and heating systems play a major role in these plans. Gas boilers rely on fossil fuels, which means they produce direct carbon emissions when operating.

Heat pumps, on the other hand, run on electricity and do not burn fuel directly within the home. As the UK electricity grid continues to incorporate more renewable energy sources such as wind and solar power, the overall carbon impact of heat pumps can continue to fall.

Because of this, heat pumps are widely seen as one of the key technologies supporting the transition to lower-carbon heating.

Government support schemes such as the Boiler Upgrade Scheme are intended to encourage homeowners to install heat pumps instead of replacing older fossil fuel systems.

While gas boilers are still widely used, the long-term direction of energy policy suggests that electric heating technologies such as heat pumps are likely to become more common in the coming decades.

Typical Scenarios: When Each System Makes Sense

Rather than thinking about heat pumps and boilers as competing technologies, it can be more useful to consider the situations where each system tends to perform best.

Scenario 1: Replacing an Old Gas Boiler

If a homeowner already has a gas connection and a compatible heating system, replacing an ageing boiler with a newer gas boiler is often the simplest option.

The installation process is usually straightforward and the upfront cost is relatively low.

Scenario 2: Rural Property Replacing Oil Heating

For homes currently heated with oil boilers, heat pumps can sometimes provide a more efficient and environmentally friendly alternative.

In these cases the difference in running costs between systems may be smaller, making heat pumps an attractive option.

Scenario 3: New Build Homes

Newly built homes designed to modern energy standards are often well suited to heat pumps. Their low heat demand allows the system to operate efficiently at lower temperatures.

Scenario 4: Major Home Renovations

If a property is undergoing extensive renovation work, upgrading insulation and heating systems at the same time can make installing a heat pump much easier.

This allows the heating system to be designed specifically for lower-temperature operation.

Heat Pump vs Gas Boiler: Key Differences

Both heat pumps and gas boilers can provide reliable heating for UK homes, but they operate in very different ways. Understanding the key differences can help homeowners decide which option best suits their property and long-term plans.

Gas boilers generate heat by burning natural gas, providing high-temperature water to radiators and hot water systems. This approach is familiar, relatively inexpensive to install and works well with many existing heating systems.

Heat pumps operate by transferring heat from outside air or the ground into the home. Instead of burning fuel, they use electricity to move heat energy. Because of this process, heat pumps can achieve very high efficiency levels compared with conventional boilers.

However, achieving the best performance from a heat pump usually depends on having a well-insulated home and a heating system designed for lower flow temperatures.

Pros and Cons of Heat Pumps vs Gas Boilers

Advantages of Heat Pumps

• very high efficiency compared with traditional boilers
• lower carbon emissions
• compatible with renewable electricity
• eligible for government installation grants
• stable and consistent heating when properly configured

Advantages of Gas Boilers

• lower installation costs
• familiar technology for most households
• high-temperature heat suitable for older radiator systems
• simple installation when replacing an existing boiler

Potential Drawbacks of Heat Pumps

• higher upfront installation costs
• may require radiator upgrades or insulation improvements
• installation can be more complex

Potential Drawbacks of Gas Boilers

• reliance on fossil fuels
• carbon emissions during operation
• less efficient compared with heat pump technology

Which Heating System Should You Choose?

There is no single answer that suits every home. The best heating system depends on the property, the heating system already installed and the homeowner’s long-term priorities.

Gas boilers remain a practical solution for many homes, particularly when replacing an existing boiler with minimal changes to the heating system.

Heat pumps can be an excellent choice for homes with good insulation, modern heating systems and homeowners looking to reduce carbon emissions and invest in long-term energy efficiency.

Many households considering heat pumps also want to understand the wider cost implications. If you are comparing systems, it may help to review the full guide to heat pump installation costs in the UK as well as the breakdown of heat pump running costs.

Ultimately, the most suitable option will depend on the specific property and how the heating system is designed.

Conclusion

Choosing between a heat pump and a gas boiler involves weighing installation costs, running costs, property suitability and long-term energy goals. While gas boilers remain common across the UK, heat pumps are increasingly becoming a popular option as homeowners look for efficient and future-ready heating systems.

Understanding the differences between these technologies can help homeowners make informed decisions about the most suitable heating solution for their property.

Heat Pump vs Gas Boiler FAQs