Heat pump vs oil boiler: which is best for your home?

What is an oil boiler?

An oil boiler heats water by burning heating oil in a fuel chamber. A heat exchanger transfers the generated heat to water, which then circulates through radiators or underfloor heating systems to warm your home.

Oil boilers are typically installed in properties not connected to the gas network, which is still common in many rural areas and smaller towns across Europe.

Fuel is stored in an on-site oil tank, which requires regular refilling by delivery. Efficiency can vary depending on the model and maintenance, but the average lifespan of an oil boiler is around 12–15 years.

Because oil boilers rely on combustion, they generally require more maintenance than modern alternatives. Over time, soot can accumulate inside the system, reducing heat transfer efficiency by preventing the heat exchanger from reaching optimal temperatures. In addition, heated soot itself is an inefficient medium for producing usable heat, which can further impact performance and increase energy consumption.

What is a heat pump?

A heat pump extracts low-temperature heat from the environment and raises it to a usable level indoors. Instead of generating heat through combustion, it moves heat from outdoor air or the ground into your home. The system works by absorbing heat from outside, compressing it via a refrigerant cycle, and transferring it into your heating system or hot water supply.

Heat pumps typically last 15–20 years and require less complex maintenance than oil boilers. Because they use electricity to move heat rather than produce it, they achieve a Seasonal Coefficient of Performance (SCOP) of around 4. This means that for every unit of electricity consumed, they can deliver approximately four units of usable heat energy.

Modern systems, such as those available from Daikin, are designed to operate efficiently even in freezing conditions, making them suitable for a wide range of European climates.

Heat pump vs oil boiler: key differences at a glance

Below is a side-by-side comparison of oil boilers and air-source heat pumps, covering cost, efficiency, performance and long-term value.

Head-to-head comparison overview

Installation and upfront costs

Installation process compared

Installing a traditional oil boiler can involve significant work, including placing or replacing a fuel tank, potentially excavation works, fitting a flue, and connecting the system to the home’s heating circuit. For homes already configured for oil heating, installation may still take several days depending on the setup.

A heat pump installation is generally more involved. It requires installing an outdoor unit (compressor) along with an indoor hot water cylinder or buffer tank. Because heat pumps operate at lower flow temperatures, installers must assess the home’s heat loss to ensure radiators are correctly sized and the system is properly balanced.

In older properties, this may involve upgrading insulation or replacing radiators to maintain comfort and efficiency. However, once installed, heat pumps eliminate the need for fuel storage and regular fuel deliveries, simplifying long-term operation.

Cost of installation

For an average-sized home, installing an oil boiler typically costs between €3,000 and €6,000, depending on the property size, system type, and whether a new oil tank is required.

By comparison, air-source heat pumps generally cost between €8,000 and €16,000 before subsidies. The final cost depends on factors such as property size, insulation quality, radiator compatibility, and any additional upgrades required.

Many European countries offer financial support schemes, including grants, subsidies or reduced VAT for renewable heating systems. These incentives can significantly lower the upfront investment for heat pumps.

While the initial cost of a heat pump is higher, it should be considered alongside long-term savings on energy bills and maintenance, as well as potential future costs such as carbon taxes on fossil fuels.

Running costs and long-term savings

Running costs and efficiency

Running costs depend heavily on fuel type, energy prices and property efficiency. Oil boilers rely on heating oil, which is typically priced between €1.39 and €1.74 per litre. A standard three-bedroom home using an oil boiler may consume around 2,500–3,000 litres per year, making annual costs highly sensitive to price fluctuations.

By contrast, air-source heat pumps use electricity to move heat rather than generate it, making them significantly more efficient. With a Seasonal Coefficient of Performance (SCOP) of 3 to 4, they produce 3–4 kWh of heat for every 1 kWh of electricity consumed.

At an average electricity price of around €0.28 per kWh, a typical household can expect annual heating costs of approximately €1,800 to €2,500 — often up to 50% lower than oil-based systems, depending on usage and local energy prices.

It’s important to note that insulation plays a critical role for both systems. Poorly insulated or air-leaky homes lose heat more quickly, reducing comfort and efficiency while increasing overall energy costs.

Which system is cheaper in the long run?

Long-term heating costs are influenced by fuel prices, system efficiency and maintenance requirements. Oil prices can be volatile, making running costs less predictable, whereas heat pumps offer more stable and typically lower operating costs, often delivering around 50% savings compared to oil.

Although heat pumps involve a higher upfront investment (typically €8,000 to €16,000), many homeowners recover this cost within 8 to 12 years through lower energy bills and reduced maintenance needs.

Oil boilers require ongoing fuel deliveries and regular servicing, while heat pumps benefit from simpler maintenance and no fuel storage requirements. Additional savings can be achieved by combining a heat pump with solar PV panels or time-of-use electricity tariffs, further reducing energy costs.

Over a typical 15–20 year lifespan, these factors make heat pumps a cost-effective and future-proof heating solution, particularly as electricity grids continue to decarbonise and fossil fuel costs remain volatile.

Fuel storage and space requirements

Oil boilers require an on-site fuel tank, which must be installed outdoors in a protected location with sufficient space. Typical tank sizes range between 1,000 and 2,500 litres, making them relatively bulky and visually intrusive. These tanks also pose an environmental risk: leaks can lead to soil contamination, and in many cases, legal responsibility falls on the homeowner.

By switching to a heat pump, you eliminate the need for fuel storage and deliveries entirely, freeing up outdoor space and removing contamination risks.

Heat pumps instead require:

• An outdoor compressor unit
• Indoor components such as a hot water cylinder and/or buffer tank

Overall, the outdoor unit is typically more compact and less obtrusive than a large oil tank.

Maintenance and servicing

Oil boilers require annual servicing, including filter replacement and soot removal, and carry an ongoing risk of tank-related issues such as tank leaks. Because they rely on combustion, they generally experience more wear and higher maintenance requirements over time.

Heat pumps, by contrast, have fewer moving parts and no combustion, which reduces wear and simplifies upkeep. While annual servicing is still recommended, modern systems benefit from built-in self-diagnosis and intelligent monitoring that detects issues early. This means maintenance is typically simpler, more predictable, and more cost-effective.

Compatibility with radiators and homes

Many homeowners ask whether existing radiators can be used with a heat pump. While oil boilers typically work with standard radiators, heat pumps operate at lower flow temperatures, which may require larger or additional radiators to maintain the same comfort level.

A heat loss analysis is essential to determine whether your home is ready and to ensure correct radiator sizing.

Insulation also plays a key role. Well-insulated walls, roofs, and floors help maintain stable indoor temperatures, improve system efficiency, and reduce running costs. In poorly insulated homes, upgrades may be needed before installing the heat pump. When combined with correctly sized radiators, good insulation ensures even, efficient, and comfortable heating throughout the home.

Environmental impact and carbon emissions

Switching from an oil boiler to a heat pump can deliver a significant reduction in carbon emissions.

As electricity networks incorporate more renewable energy, heat pumps become progressively cleaner and play a key role in achieving the EU’s net-zero targets.

For even greater impact, homeowners can combine a heat pump with solar PV (photovoltaic) panels, which allows you to cut heating costs while lowering reliance on imported oil and supporting the energy transition.

Emissions compliance and future regulations

Meanwhile, across Europe, many nations have far tighter rules on carbon emissions from domestic heating. Fossil fuelled boilers are progressively being restricted, and certain countries plan to stop new ones from being put in within the next 10 years.

Heat pumps support decarbonisation objectives and are frequently backed by regulatory incentives. Investing in the right technology provides a future-proof, low-carbon solution that minimises legal and financial exposure.

Government grants and incentives

Across Europe, many countries are introducing stricter regulations on carbon emissions from domestic heating, and fossil-fuelled boilers are progressively being restricted. At the same time, financial incentives are available in many European countries to support the adoption of low-carbon heating systems such as heat pumps. While schemes vary by country, it’s important to check eligibility criteria (often depending on certified installers, property type, or technical assessments) and what the programme covers, such as insulation upgrades or radiator replacements.

Performance and reliability

Heating performance and temperature control

While oil boilers deliver high flow temperatures (around 70°C), heat pumps operate at lower temperatures (35–45°C). Instead of intense bursts of heat, systems such as underfloor or radiant heating provide a more gentle and consistent warmth throughout the home.

A key advantage of heat pumps is the ability to maintain stable indoor comfort (typically 19–21°C) without the on/off cycling, noise, or vibration often associated with oil boilers.

Modern systems further enhance performance through:

• Smart controls and zoning, delivering heat only where and when needed
• Timed schedules, reducing unnecessary energy use
• Advanced solutions like Daikin control systems, enabling individual room airflow and temperature management

This results in greater comfort, improved efficiency, and reduced energy waste.

Reliability and cold weather performance

Modern air-source heat pumps are designed to perform efficiently even in sub-zero temperatures. Unlike oil boilers, which depend on fuel deliveries that may be disrupted in severe weather, heat pumps provide consistent and reliable heating when correctly sized and installed.

Daikin units are tested for extreme cold conditions and include built-in protections for both indoor and outdoor components, ensuring performance and efficiency are maintained even in freezing climates.

Safety comparison

Oil boilers carry risks such as tank leaks, which can contaminate soil, and carbon monoxide from combustion, particularly if the system is poorly maintained. Heat pumps, running electrically without combustion, eliminate these risks. With fewer moving parts and lower thermal stress, they are mechanically more reliable.

Daikin’s Stand By Me service offers online diagnostics, giving peace of mind by detecting performance issues early.

Hybrid heating systems

Hybrid systems combine a heat pump and an oil boiler, allowing homeowners to switch between systems based on outdoor temperature and energy tariffs (e.g. day-rate vs night-rate electricity). In this setup, the heat pump typically covers most of the heating demand, while the oil boiler provides additional support during very cold periods.

This can be an effective solution for homes that are not fully optimised for low-temperature heating. However, hybrid systems are more complex to install and maintain, increasing upfront investment.

Over time, they can still deliver reduced fuel consumption and lower emissions compared to oil-only systems.

Smart tech and connectivity

Modern heat pumps integrate seamlessly with smart thermostats and app-based controls, giving homeowners greater control over energy use and comfort.

With solutions like Daikin Cloud Service (DCS), you can monitor real-time energy use and optimise performance.

Features such as load shifting and smart grid compatibility further improve efficiency—especially when combined with solar PV systems or time-of-use electricity tariffs. In contrast, oil boilers typically rely on manual timers and offer limited flexibility.

Smart technology also enables remote diagnostics via Daikin’s Stand By Me service, which tracks system performance and schedules maintenance proactively.

Final thoughts on heating choices

Choosing between an oil boiler and a heat pump ultimately depends on a home’s style, budget, and long-term goals. Oil boilers may offer lower upfront costs and quick high-temperature heating, but they come with higher running costs, emissions, and regulatory risk. Heat pumps, while requiring a greater initial investment and careful system design, deliver higher efficiency (SCOP 3–4 vs. 60–93%), lower lifetime costs, improved comfort, and up to 80% lower carbon emissions than oil boilers. As energy prices fluctuate and climate regulations tighten, heat pumps represent a more resilient, future-proof heating solution, particularly when combined with good insulation, smart controls, and renewable electricity sources.

Key takeaways

• Oil boilers rely on combustion and fuel storage. They require on-site tanks, regular deliveries, and annual servicing.
• Heat pumps are significantly more efficient.
• Running costs are lower with heat pumps. Heating an average European home with oil can cost €3,500–€5,500 per year, versus €1,800–€2,500 with an air-source heat pump.
• Heat pumps dramatically reduce carbon emissions. Switching from oil can cut emissions up to 80%, with further reductions as electricity grids decarbonise.
• Home efficiency impacts performance. Proper insulation and correctly sized radiators are essential for maximising comfort and efficiency.
• Heat pumps are a future-proof solution. They are aligned with EU decarbonisation targets, benefit from incentives, and typically last 15–20 years.