Heat Pump Vs. Boiler: A Detailed Comparison!

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By Debarghya Roy


Heat pumps and boilers are two of the most common heating options available, but which one will best meet your home heating needs? Comparing these two systems can be complex due to their different mechanisms for generating heat. In this blog post, we’ll look at the various aspects of both types of heating, from their efficiency and cost to their environmental impact and installation requirements in order to see which option is a better choice for your specific circumstances.

Heat Pump Vs. Boiler

Image of a heat pump and a boiler

Key Takeaways

  • Heat pumps have a higher energy efficiency rating than modern gas boilers, with up to 300% AFUE compared to 98.5%.
  • Heat pumps require minimal maintenance in comparison to boilers and can last up to 30 years, whereas most boilers only have an average lifespan of 10-15 years.
  • Air source heat pumps are suitable for most climates due their multiple independent defrost cycles running throughout extreme weather conditions.
  • The installation costs of heat pump systems may be higher than traditional boiler systems however they will save money over time by reducing fuel consumption and carbon emissions associated with burning fossil fuels used in gas boilers

What Is The Difference Between A Heat Pump And A Boiler?

The primary difference between a heat pump and a boiler is that while the former uses as external energy source to both heat and cool, the latter only provides direct heating from burning fuel.

Operating Mechanism

Heat pumps and boilers both provide heat for homes and buildings, but the way in which they do this is very different. 

Heat pumps use electric energy and refrigerant to capture naturally occurring thermal energy from air, water or underground rock layers (ground source) to generate heat. This absorbed thermal energy transfers through small pipes found within walls where it is released into a home or building as warm air. 

Boilers, on the other hand, work by converting stored chemical energy (such as gas or oil) into kinetic energy, turning water into steam. That is then pumped through radiators to produce warmth inside of living spaces.

Both kinds of systems are reliable heating solutions, but depending upon your environment could be more cost-effective than others.

Energy Efficiency

When making a choice between a boiler and a heat pump, the issue of energy efficiency is perhaps one of the most important factors to consider. 

The efficiency rating of your heating device is measured in terms of how much energy it requires to function in comparison to what it produces.

Two common measurements used when comparing boilers and heat pumps are their coefficient of performance (COP) and annual fuel utilization efficiency (AFUE). 

Boilers generally have an AFUE range from 89-98%, while heat pumps can reach up to 400% COPs due to their ability to transfer rather than create heat.

This difference in capacity leads directly into reduced running costs over time compared with boilers since more heated air or water will be produced per watt consumed.

By improving your home’s overall energy efficiency, you may even be eligible for state-level tax credits or government grants that help offset some of the financial expenses associated with installation.

Heating And Cooling Capabilities

Both boilers and heat pumps have distinct capabilities when it comes to heating and cooling your home. 

Boilers are typically used for consistent, temperature-controlled heating of spaces such as houses or apartments, with forced hot water being circulated through radiators or heating coils in walls and floors. Boilers can also be connected to air conditioning units whereby warm air is recycled throughout the property several times per hour using a series of ducts. 

Heat pumps on the other hand, move rather than generate heat which means that they are capable of both providing cooling in summer months as well as warming during winter months.

Air-source heat pumps extract warmth from the outside atmosphere with an indoor unit located either at ground level or mounted on a wall converting extracted energy into usable form, while ground source heat pump is more suitable for use if you own an outdoor space such as a garden due to its need for underground piping system running through this area to absorb ambient thermal energy beneath the surface.

Heat Pump Vs Boiler: Efficiency And Cost

Comparing the efficiency of a heat pump and boiler requires looking at not only energy efficiency, but also cost-effectiveness due to fuel consumption rates.

Energy Efficiency Comparison

Energy efficiency is a crucial factor to consider when comparing heat pumps and boilers, as it has a significant impact on the overall cost of the heating system and its environmental footprint. 

The Annual Fuel Utilization Efficiency (AFUE) rating system measures the energy efficiency of heating systems, such as heat pumps and boilers, by calculating the ratio of heat output to the total energy consumed. The higher the AFUE percentage, the more efficient the system.

Heating SystemEnergy Efficiency (AFUE)
Heat PumpsUp to 300%
Gas Boilers80% – 98.5%
Oil Boilers80% – 90%
Electric Boilers95% – 100%

As illustrated in the table above, heat pumps offer exceptional energy efficiency compared to traditional gas, oil, or electric boilers. 

With an AFUE of up to 300%, heat pumps can save consumers up to 27% on their heating bills compared to gas boilers. Modern gas boilers can provide AFUE ratings as high as 98.5%, but heat pumps remain more energy-efficient, making them an ideal choice for homeowners looking to reduce energy costs and their carbon footprint.

Cost Comparison

When comparing the costs of heat pumps and boilers, it’s essential to take into account various factors that can impact the overall cost of ownership, such as installation costs, maintenance expenses, and energy efficiency ratings. In this section, we will break down the cost differences between heat pumps and boilers to help you make an informed decision.

FactorsHeat PumpBoiler
Installation Costs£7,000 – £13,000Lower compared to heat pumps
Operating Costs£723 per year (very efficient)£536 per year (gas boiler)
Maintenance ExpensesLower compared to boilersHigher compared to heat pumps
Energy Efficiency RatingsHigher compared to boilersLower compared to heat pumps

It’s important to note that while heat pumps may have higher installation costs, they can be less expensive to operate and maintain over time. This is especially true when compared to less efficient or older gas boilers, where the cost savings from using a heat pump become more significant. On the other hand, gas boilers have lower installation costs, which may be more appealing to some homeowners.

Various factors can affect the overall cost of ownership for both heat pumps and boilers. For example, a home situated in a colder climate may require additional backup heating sources or supplementary insulation, adding to the initial installation costs for a heat pump. 

Similarly, a boiler that needs frequent repairs or maintenance may end up costing more in the long run compared to a heat pump with minimal maintenance requirements.

Ultimately, the best heating technology for your home depends on your specific needs, efficiency requirements, and budget. By assessing these factors, you can make an informed decision about whether a heat pump or a boiler is the right choice for you.

Heat Pump Vs Boiler In Cold Climates

In cold climates, heat pumps can often outperform boilers in terms of energy efficiency even during extreme weather conditions.

Performance In Extreme Weather Conditions

When extreme weather conditions hit, the performance of different types of heating systems varies greatly. A traditional gas boiler is not normally considered suitable for cold climates as they are prone to breakdowns in sub-zero temperatures.

Heat pumps, on the other hand, can still operate effectively in colder climates and use energy more efficiently than boilers; however, their efficiency also drops significantly if the temperature falls below freezing.

To ensure optimal functioning during winter months, an air source heat pump will require a “defrost” cycle that turns off the heating while it works to thaw out external components that may have frozen overnight due to low outdoor temperatures.

Ground or water source heat pumps don’t suffer from this problem as they draw their warmth from deeper layers underground or from bodies of water that remain at a relatively consistent temperature throughout winter.

Some modern oil boilers are also now available and designed specifically for usage in extremely cold locations where electricity infrastructure might not reach.

Defrost Cycles

Heat pumps help to cool and heat a home by transferring energy from one place, such as the outside air, to another, like the inside of a home. During operation, moisture in the outdoor coil can freeze and block airflow over the coil which decreases system output.

To avoid this, most heat pumps have a defrost cycle designed to reverse condensation buildup or ice accumulation on cold surfaces. The cycle works by applying small amounts of electrical current to heat up an outdoor element when necessary conditions are met in order for the refrigerant flow to resume more efficiently throughout cold conditions and only lasting for few minutes at any time.

Heat Pump Vs Boiler: Reliability And Lifespan

The reliability and lifespan of a heat pump vs. boiler is explained below.

Lifespan Comparison

The lifespan of a heating system is a crucial factor to consider when choosing between a heat pump and a boiler. A heat pump has a longer lifespan, lasting up to 30 years, while a boiler has an average lifespan of 10 to 15 years. To maximize the longevity of these systems, regular maintenance is essential. Here is a comparison of the maintenance requirements for heat pumps and boilers:

Maintenance TaskHeat PumpBoiler
InspectionAnnual professional inspectionAnnual professional inspection
Filter replacement or cleaningEvery 1-3 months (varies depending on use and filter type)Not applicable, as boilers do not use filters
Refrigerant checkAnnual check by a professionalNot applicable, as boilers do not use refrigerants
Heat exchanger cleaningAs needed, to be assessed during annual inspectionEvery year, usually during annual inspection
Outdoor unit cleaningEvery year, as part of regular maintenanceNot applicable, as boilers do not have an outdoor unit
Pump maintenanceEvery 3-5 years, or as recommended by the manufacturerNot applicable, as boilers do not use pumps
Pressure checkNot applicable, as heat pumps do not use pressurized systemsEvery year, usually during annual inspection

This table highlights the differences in maintenance tasks required for heat pumps and boilers. By adhering to these maintenance schedules, homeowners can prolong the lifespan of their heating systems, making a heat pump a more reliable and long-lasting option for home heating.

Maintenance Requirements

Both heat pumps and boilers require regular maintenance to keep them running properly. Heat pumps typically need an annual check-up, filter changes, air handler checks, refrigerant charge topping up or replacement periodically as required and lubrication of all moving components at least once a year.

In contrast, boilers usually only need yearly safety inspections and more in-depth servicing every few years when their filters become blocked with debris and dirt. On top of this, they may also need system balancing tests as the unit ages.

To prevent wear on the internal components it is important to have boiler flushing done regularly to ensure that any corrosive by-products from burning fuel are completely removed before corrosion sets in.

Since heat pumps move both warm/cool air inside buildings while transferring energy between two separate units (an indoor unit located inside the building and an outdoor unit), ensuring its cooling coils are clean is also necessary so it can efficiently transfer energy between those two points without losing it into the atmosphere outside due to clogged fins on either coil set. This needs professional help if you’re not confident working on such intricate machinery yourself.

Backup Heating Sources

Having a backup heating source is important for both houses with boilers and those with heat pumps to ensure comfortable temperatures are maintained throughout the cold winter months.

Electric resistance heaters, powered by electricity or natural gas, offer a reliable form of supplementary heating should the primary system fail or experience difficulty in colder climates.

Other types of backup sources include carbon monoxide-free Corn Stoves and pellet stoves that burn wood pellets for energy. Some ductless mini-splits can also act as emergency back-up furnace systems when weather temperatures drop too low for standard air/water source models.

When choosing a primary heating technology, it’s essential to consider what type of short or long-term backup may be necessary during extreme weather conditions or outages given the property’s age and location.

Heat Pump Vs Boiler: Environmental Impact

Both heat pumps and boilers generate heat for heating homes or buildings, however, the environmental impact of each is quite different. 

While a boiler runs on fuel such as gas, oil or propane to burn and produce energy, a heat pump harnesses ambient air, water or ground temperatures to gently transfer already existing heat.

Carbon Footprint Analysis

Heat pumps and boilers emit carbon dioxide into the atmosphere, but heat pumps release less than half of the carbon dioxide compared to a boiler. With gas-fueled boilers, burning fossil fuels results in direct emissions that can pollute the surrounding environment.

Heat pumps work differently since they transfer existing ambient energy from outside air or underground water sources to indoor spaces. This process does not directly produce any emissions, however requires electricity so careful analysis is needed for a proper comparison between heating systems.

The total carbon footprint also depends on factors such as how much renewable energy such as solar panels are available in an area and whether there is access to alternative energies like hydrogen fuel cells or geothermal resources.

In addition considering what type of heat pump system you will need for your home along with its associated installation cost should be taken into account when performing a carbon footprint analysis.

It is important to note that ground source heat pumps have lower installed costs but often require more space which can cause additional pollution due to increased excavation activity near buildings and homes located nearby.

Air source units may ultimately have higher electric bills, however, they take up significantly less outdoor space making them an efficient option for urban areas where space is limited and don’t require long piping turned through wild landscaping activities around property lines affected by their presence.

Use Of Renewable Energy Sources

Heat pumps used in conjunction with renewable energy sources, such as solar or geothermal energy, are the most efficient and environmentally friendly choice when it comes to residential heating systems.

Utilizing these alternative energies makes it possible to reduce both the environmental impact of a home’s heating needs while also significantly reducing costs. In addition, many governments offer incentives and rebates for utilizing renewable energy sources that can further drive down installation costs.

For instance, some governmental bodies provide grants if a homeowner installs an air source heat pump powered by solar panels on their property. Another example is authorities providing subsidies if homeowners upgrade their gas boilers using new hydrogen-ready boilers which run off of hydrogen fuel.

Heat Pump Vs Boiler: Installation And Retrofitting

Comparing the cost of installation, retrofitting options and long-term incentives for both Heat Pump and Boiler systems is important to make an informed purchasing decision.

Installation Costs

When it comes to the installation of heat pumps and boilers, there are a variety of factors that need to be taken into consideration which can affect cost. These include size and type of unit installed, the complexity of the system for the particular installation site, as well as geographical location.

For instance, air-source heat pump units typically range from $3,500-$7,500 in combined installation and unit costs, alternatively, ground source heat pumps may cost upwards of tens of thousands depending on individual circumstances.

A gas boiler replacement meanwhile can cost £1 – 2k depending on incoming pipework complexity while hydrogen-ready boilers will likely require specialist input with commensurate higher costs.

In addition to these direct installation costs associated with replacing existing systems or setting up temperature control networks in new developments/ premises & buildings, property owners should also consider factors such as potential government incentives in their calculations when choosing between different solutions. There are several options related to that, such as cashback saving schemes for installing renewable heating systems (such as allowing homeowners subsidies/rebates covering up to half the purchase price), bonus payments toward energy efficient appliances & technologies (allowing customers to cover some of their initial investment) & offers targeting lower-income households via referral services like ECO grants/funding etc.

Retrofitting Options

Retrofitting a building with either a heat pump or boiler allows for higher energy efficiency and lower costs in the long run. While retrofitting or replacing existing systems may involve an initial upfront cost, there are many ways that homeowners and businesses can save on electricity bills over the lifetime of their systems.

For example, installing pipes into underground spaces to gain access to geothermal sources of heating is often much more efficient than traditional boilers as it is better able to retain warmth in extreme weather conditions.

Additionally, modern boilers and pumps contain advanced features such as flue pipe temperature sensors and insulation which help them work at peak efficiency.

Programmable thermostats can also be installed which ensures you don’t waste energy by running your heating unnecessarily when no one is home or while you sleep. Retrofit options such as these have been known to decrease annual electricity bills depending upon how balanced heating needs across seasons are managed.

Heat Pump Vs Boiler: Government Incentives And Rebates

Government incentives and rebates are available for both heat pumps and boilers, encouraging homeowners to switch to more energy-efficient and cost-effective heating systems.

Available Incentives And Rebates

The Inflation Reduction Act offers various federal tax credits and state rebates for purchasing heat pumps, heat pump water heaters, or biomass stove/boiler. The annual total limit for these incentives is $2,000 for any combination of the above appliances. 

Homeowners can receive a maximum tax credit of $2,000 in order to install electric heat pumps or heat pump water heaters as well as biomass stoves and boilers.

These incentives are quite useful to many Americans due to the attractive financial benefits associated with taking such measures under the current climate law from Joe Biden’s Administration. 

Eligibility criteria include installing an energy-efficient appliance and meeting specific other requirements depending on particular type of appliance purchased.

For instance, when buying different types of air source heat pumps homeowners may qualify for up-front cost reimbursements between £850 -£6,400 while ground source may attract up-front incentive replacements up to £20,500. Meanwhile, boiler upgrades scheme helps households replace either a gas boiler or fossil fuel system into cleaner-burning one by entitling them to receive cashback savings careered at 45 pence per kilowatt hour saved incentivized saving till 31 March 2022.

Eligibility Criteria

Government incentives and rebates are available to those who qualify in the purchase of a heat pump or boiler. For example, through the Inflation Reduction Act you may be eligible for tax credits of up to $2,000 if you buy an ENERGY STAR certified piece of equipment.

Those living in low-income census tracts or non-urban areas may also be eligible for a 30 percent tax credit on the cost of charging/refueling their heat pumps.

The Build Better Act offers even more generous rebates up to USD 4,000 for large heating solutions intended for cold climates in the United States. Qualifying household must meet certain criteria determined by local governments and utility companies before claiming these incentives and rebates.


What is the difference between a heat pump and a boiler?

The main difference between a heat pump and boiler is that boilers use fossil fuels such as oil or natural gas to produce hot water or steam which then circulates through heating pipes while heat pumps extract energy from the air, ground or water source to deliver hot air into your property.

What are the pros and cons of using a heat pump versus a boiler for home heating?

A Heat Pump can boast better energy efficiency than an older boiler system at roughly 75-80 percent compared to 65–70 percent with high-efficiency boilers resulting in lower energy bills. On the downside, installation costs for new systems can tend to be higher than with other types of fuel sources due to the additional equipment needed (i.e., outdoor unit). In comparison boilers tend to be less expensive upfront but require more frequent maintenance & repairs ensuring their lifespan remains intact over time making it not cost-effective if ignoring necessary servicing often enough (which may outweigh any initial savings when taking longevity into account).

Can I install both systems in my home?

Yes, you could certainly install multiple units depending upon budget & space available however doing so may nullify any potential benefits since operating each system independently will likely consume far more electricity/energy than having them work together depending on temperatures outside ie summer months relying solely on air conditioning while winter utilizes both simultaneously for maximum warmth & comfortability within home surroundings without either one carrying too much workload during specific seasons/times throughout year ultimately leading users having experience highest extra costs incurred due saving resources equally across board instead of just handful items running continually absorbing majority power exclusively vice versa etc.

How does geothermal cooling differ from traditional AC units?

Geothermal cooling uses deep wells, rather than condensing coils, in order to capture cooler underground temperatures and transfer those temperatures inside by means of liquid-cooled loops which reduce the amount of electricity needed to ensure comfortable indoor climates despite extreme weather patterns influencing climate outdoors at a time allowing individuals enjoy savings based usage principles laid out beforehand without worrying about skyrocketing bills halfway thru month thanks combination technological advancements being utilized various contexts thus ensuring optimal results no matter conditions


In summary, heat pumps and boilers are two efficient heating systems that have distinct advantages. Heat pumps are more energy-efficient than modern boilers with up to 98.5% AFUE but require a source of heat from outside the home such as air or ground. Boilers are powered by burning fuel like natural gas to generate heat for specific areas in the home, providing a sprinter-like performance compared to the moderate and continuous pace of a heat pump. Taking into account factors such as efficiency, cost, reliability, lifespan, environmental impact and installation costs is key when selecting either option as it may make one better suited for your unique needs than the other.

Heat Pump