Heat Pumps vs Gas Boilers

In the quest for eco-friendly and cost-effective home heating, the debate between heat pumps and gas boilers is heating up. This ‘heat pumps vs gas boilers’ comparison aims to shed light on the pros, cons, costs, and efficiencies of both. Whether you’re considering installing a heat pump or a gas boiler, this guide will help you make an informed decision that’s right for your home and pocket.


Gas Boiler vs Heat Pump Installation Process

Gas boiler installation process

Installing a gas boiler is a familiar procedure in many UK homes. It’s a straightforward process, often completed within a day or two, especially if it’s a simple replacement. Gas boilers are compact, and the main components are usually stored out of sight, like in a utility room or loft.


  1. Choose the right type of gas boiler for your home’s needs.
  2. Prepare the installation site, ensuring proper ventilation and access.
  3. Remove the old boiler, if replacing it.
  4. Install the new boiler by connecting it to the existing gas network.
  5. Set up the flue to safely expel gases.
  6. Connect the boiler to the central heating system.
  7. Test the boiler to ensure it’s working efficiently.

Heat pump installation process

Heat pumps, whether air source or ground source, have a slightly more complex installation process. The installation might take a bit longer, especially for ground source heat pumps which need digging. But, the benefits of a heat pump, such as low-carbon heating, often make the effort worthwhile.


  1. Decide between an air-source heat pump or a ground-source heat pump.
  2. For a ground source heat pump, dig trenches or boreholes in your garden.
  3. Install the heat pump unit outside your home.
  4. Connect the pump to your home’s heating system.
  5. Set up the necessary electrical connections.
  6. If using an air source heat pump, install the external fan unit.
  7. Test the system to ensure optimal performance.

Please note that although these steps seem relatively straightforward, it’s not recommended to install either a gas boiler or heat pump system by yourself. In fact, in the UK, any ‘work in relation to gas’ has to be done by a Gase Safe registered engineer.

Similarly, installing a heat pump should only be done by a qualified professional, although competent DIYers can handle things like the basic pipework, so long as it’s in line with the design laid out by the system designer.

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Gas Boiler vs Heat Pump Installation Costs

Gas boiler installation costs

When considering a gas boiler to heat your home, it’s important to factor in the installation costs. Generally, gas boilers have a lower upfront cost compared to heat pumps. But, the exact price can vary based on the type and brand of the boiler, as well as the complexity of the installation.

Cost breakdown:

  • Boiler unit: Typically, the boiler itself can range from £500 to £2,500.
  • Labour: Installation by a Gas Safe registered engineer can cost between £500 and £1,000.
  • Additional parts: Flue, thermostat, and other essential components might add up to £200 or £400.
  • Removal of old boiler: If replacing your boiler, disposal fees can be around £50 to £100.

Heat pump installation costs

Opting for a heat pump vs a gas boiler might mean a higher initial investment, but it can lead to long-term lower energy bills and reduced carbon emissions. The installation costs for heat pumps can be steeper because of the complexity of the system and the need for specialised equipment.

Cost breakdown:

  • Heat pump unit: Depending on the type (air or ground source), prices can range from £6,000 to £12,000.
  • Labour: Installation costs can vary between £1,500 and £3,000.
  • Groundwork: For ground source pumps, digging trenches or boreholes can add £3,000 to £6,000.
  • Additional equipment: Piping, thermostat, and other components might total £500 or £1,500.

Again, it’s important to bear in mind that the cost of both of these systems can change according to the market. If you’ve got your eye on a heat pump but are slightly put off by the upfront cost, do some research to see if you qualify for a heat pump grant, specifically the ECO4 scheme.

boiler fitter

Gas Boiler vs Heat Pump Running Costs

Gas boiler running costs

Gas boilers have been the traditional choice for many UK homes, primarily because of the existing gas network and the familiarity with the system. While the initial setup might be more affordable, the ongoing costs can fluctuate based on gas prices and the boiler’s efficiency. Regular maintenance is also a factor to consider when calculating the total running costs.

Cost breakdown:

  • Gas bills: Depending on usage and tariffs, homeowners might spend between £400 and £1,500 annually.
  • Maintenance: Yearly servicing by a Gas Safe engineer can cost around £50 to £100.
  • Repairs: Unexpected breakdowns or part replacements can add up to £100 to £500, depending on the issue.
  • Efficiency loss: Older boilers might consume more gas, leading to higher bills over time.

Heat pump running costs

Heat pumps, known for their eco-friendly approach, can be a boon for those looking to reduce carbon emissions and potentially save on energy bills. While they do use electricity, their efficiency means you get more heat per unit of power consumed. However, they also need periodic maintenance to keep them running at their best.

Cost breakdown:

  • Electricity bills: Given their efficiency, annual costs can range from £300 to £1,000, depending on usage and electricity rates.
  • Maintenance: Regular check-ups and servicing might cost between £100 and £300 annually.
  • Repairs: If issues arise, repair costs can vary from £100 to £700, based on the complexity.
  • System degradation: Over time, efficiency might slightly decrease, leading to minor increases in running costs. This could also come down to whether you have an air-source heat pump or a ground-source heat pump.

The exact numbers will always vary but if you can get around the initial costs of installing a heat pump, you’ll likely find that it’ll be more cost-effective overall. Regardless, with both systems, maintenance is incredibly important. Without proper maintenance, running costs can increase by a significant amount.

In this regard, the ideal approach may be to find a qualified technician who can service your system at least once a year or as many times as specified by the manufacturer.

heat pump outside

Gas Boiler vs Heat Pump Energy Efficiency Comparison

Gas boiler energy efficiency

Gas boilers have seen significant improvements in their energy efficiency over the years. Modern condensing boilers can achieve efficiencies of up to 90-94%, meaning that for every pound spent on gas, 90-94p is directly used for heating. However, it’s worth noting that as boilers age, their efficiency can decrease, leading to more wastage and higher energy bills.

Efficiency factors:

  • Type of boiler: Condensing boilers are more efficient than older, non-condensing models.
  • Maintenance: Regular servicing ensures optimal performance and maintains high efficiency.
  • Usage: Running a boiler at lower temperatures can increase its efficiency.
  • Age: Older boilers, especially those over a decade old, can see a drop in efficiency.

Heat pump energy efficiency

Heat pumps stand out when it comes to energy efficiency. They can achieve efficiencies of 300-400%, meaning they can produce 3 to 4 times more heat energy than the electrical energy they consume. This is because they extract heat from the environment (air or ground), which requires less energy than generating heat by burning gas.

Efficiency factors:

  • Type of heat pump: Ground-source heat pumps are often more efficient than air-source heat pumps.
  • Temperature: The efficiency of heat pumps can decrease in extremely cold conditions.
  • Maintenance: Like boilers, regular check-ups ensure they run at peak efficiency.
  • Installation: Properly sized and correctly installed heat pumps can achieve their maximum efficiency potential.

Can You Have A Heat Pump & Gas Boiler?

The simple answer is yes, you can have both a heat pump and a gas boiler in your home. This combination is often referred to as a hybrid heating system. But the real question is, should you?

Can you have a hybrid heating system?

A hybrid heating system combines the strengths of gas boilers and heat pumps, be it air source or ground source. The idea is to utilise the most efficient heating method depending on the external temperature and heating demands.

  • Gas boiler: Gas boilers are excellent for providing instant heat and are especially effective during the colder months when the efficiency of some heat pumps might decrease.
  • Heat pump: Whether it’s an air source heat pump or ground source heat pump, both are most efficient during milder temperatures, extracting outside heat to warm your home.

Should you have a hybrid heating system?

Going for a hybrid heating system can give you several advantages:

  • Efficiency: By using the most efficient heating method depending on the conditions, you can optimise your energy usage.
  • Environmental impact: Heat pumps, especially air source heat pumps, have a lower carbon footprint compared to gas boilers. By relying more on the heat pump during milder temperatures, you can reduce carbon emissions.
  • Cost savings: While the initial setup might be more costly, the potential savings on energy bills can make it a worthwhile investment for the future.

Despite the potential advantages, there are some things to consider with a hybrid system. For one, the installation process can be more complex, and you’ll need space for both systems. Also, regular maintenance for both the gas boiler and the heat pump is essential to ensure they run efficiently.

While the heat pump vs gas boiler debate continues, a hybrid heating system might offer a middle ground, combining the best of both worlds. It’s also important to note that with the Scottish government’s plan to phase out gas boilers, getting a hybrid system may not necessarily be the best move.

What Type Of Home Suits A Heat Pump?

Heat pumps are becoming increasingly popular in the UK thanks to their eco-friendly nature and potential savings on energy bills. But is your home suitable for a heat pump? Let’s delve into the factors that make a home ideal for this type of heating system.

Space and location

  • Air source heat pump: These require an outdoor space to house the external unit. Ideally, this should be a spot that gets good airflow but is also protected from strong winds. The unit is similar in size to an air conditioning unit.
  • Ground source heat pumps: These require more space, as they involve underground pipes. Homes with larger gardens are more suitable, as trenches or boreholes need to be dug.


Heat pumps work best in well-insulated homes. Proper insulation ensures that the heat generated is retained, making the system more efficient. Homes with double glazing, loft insulation, and draught-proofing are ideal.

Existing heating system

Homes with underfloor heating or large radiators are more suited for heat pumps. This is because heat pumps produce heat at a lower temperature over longer periods, making these systems more effective.

Environmental considerations

For homeowners keen on reducing their carbon emissions, heat pumps are a great choice. They’re especially beneficial for homes not connected to the gas network, offering a more eco-friendly alternative to oil or electric heaters.

What Type Of Home Suits A Gas Combi Boiler?

Gas combi boilers have long been a feature in many UK homes. They offer efficient heating and hot water without the need for a separate tank. But what type of home is best suited for a gas combi boiler? Let’s explore the factors:

Size of the home

Combi boilers are particularly well-suited for smaller homes, flats, and apartments. Their compact size means they don’t require a separate hot water cylinder or cold water storage tank, saving valuable space.

Hot water needs

Combi boilers are designed to heat water on demand, so they can work well for a home with moderate demand for hot water. For homes where hot water usage isn’t simultaneous from multiple outlets, like multiple showers running at once, a combi boiler is ideal.

Existing infrastructure

Homes already connected to the gas network can easily accommodate a gas combi boiler. The installation is straightforward, especially if replacing an old gas boiler. This means that installation or replacement costs can be significantly lower.

Space considerations

One of the main advantages of combi boilers is the elimination of the need for a separate water tank. This is a huge benefit for homes with limited loft or storage space.

Efficiency and cost

For smaller households with moderate hot water needs, combi boilers can be more energy-efficient than system boilers, potentially leading to savings on energy bills.

Environmental impact

While gas combi boilers are not as eco-friendly as renewable energy sources like heat pumps, modern boilers are designed to be more efficient and produce fewer carbon emissions than older models.

So, to sum it all up, gas combi boilers are a fantastic choice for smaller homes with moderate hot water demands. Their compact design, combined with their efficiency, makes them a popular choice for many UK households, especially those already connected to the gas network.


Yes, funding is available for heat pumps in the UK. The government recognises the environmental benefits of heat pumps and offers grants, such as the ECO4 scheme, to encourage homeowners to make the switch. With the ECO4 scheme, you or someone in your house on a qualifying benefit could get an air source heat pump for free.

A heat pump is designed to last for a long time, typically around 15 to 20 years. However, its lifespan can vary based on factors like maintenance, usage, and the specific model. Regular servicing and proper care can ensure your heat pump operates efficiently for many years.

In some cases, certain manufacturers may include a service plan with the purchase of the boiler, which can save you on maintenance costs.

The UK government has plans to phase out the installation of new gas boilers in newly built homes by 2025. This move is part of a broader strategy to reduce carbon emissions and promote greener heating solutions. However, existing gas boilers in homes won’t be banned but will likely be replaced with more eco-friendly options over time.

Air source heat pumps take heat from the air outside and use it to warm your home. They’re easier to install and usually cheaper upfront. On the other hand, ground source heat pumps get heat from underground. They’re a bit more expensive to set up but can be more efficient in the long run.

While both types help reduce energy bills and are eco-friendly, your choice will depend on your budget, space, and how long you plan to stay in your home.

In terms of running costs, heat pumps can be more economical than combi gas boilers, especially in well-insulated homes. While the initial investment for heat pumps vs gas boilers might be higher, the potential savings on energy bills and the eco-friendly nature of heat pumps can make them a cost-effective choice in the long run.


In the ever-changing landscape of home heating, the debate between an air-source and ground-source heat pump vs gas boilers remains a topic of discussion. As we’ve explored, each system has its unique advantages and considerations.

While heat pumps, both air and ground source types, offer an eco-friendly solution with potential long-term savings, gas boilers provide familiarity and immediate warmth many homeowners are accustomed to. When considering a heat pump vs a gas boiler, it often boils down to individual household needs, environmental concerns, and budget considerations.

As the UK pushes towards greener energy solutions, it’s evident that heat pumps are gaining traction. However, gas boilers, especially modern, efficient models, still hold a significant place in many homes.

In short, whether you’re leaning towards the innovative efficiency of heat pumps or the tried-and-true performance of gas boilers, understanding your home’s specific needs will guide you to the best decision.