Is a heat pump worth it? Heat pump versus gas boiler costs

Take this example of two homeowners – Sophie and Marc – who each renovated their homes in Lyon, France, in 2015.

Heat pump and boiler installation costs

Sophie invested in an air-to-water heat pump, while Marc opted for a modern condensing gas boiler.

There are many different types of heat pumps, so the cost of buying and installing can vary significantly, from around €9,200 to around €20,800. There could be additional costs to consider if you decide to carry out other improvements, such as changing existing emitters, or installing insulation.

Gas boilers are generally cheaper to install, ranging from €3,000 to €6,000.

Depending on where you live though, you might be able to get a grant towards the cost of a heat pump. You can read more about incentive schemes in your area here.

The same was true for Sophie. While her installation cost was high compared to Marc’s gas boiler, she was able to offset this using a government grant.

What are the maintenance costs and lifespan

Another factor in the return on investment equation is how long your heating system will last and how much it costs to maintain and run during that time.

If looked after properly, a heat pump can last 15 to 20 years. Maintenance involves routine checks and cleaning, and typically costs around €115 to €230 per year.

Due to their combustion processes, gas boilers require careful maintenance and servicing, which can cost between €115 and €350 per year. Their average lifespan is 10 to 15 years.

Ten years after installing their new heating systems, Marc’s gas boiler is now nearing the end of its life, while Sophie can expect to get another 5 to 10 years from her heat pump.

Sophie’s maintenance costs have been low, while Marc has experienced higher maintenance costs for his gas boiler.

Energy prices and running costs

A heat pump draws up to 75% of its energy from nature for free, with the remainder powered by electricity, while a boiler relies entirely on gas. The comparative running costs therefore depend on the cost of household electricity versus gas.

Particularly in recent years, we’ve seen significant price fluctuations in natural gas, due to geopolitical tensions, market demand and supply chain disruptions. Seasonal and geographical factors also play a part and gas prices may spike during harsh winters.

While modern heat pumps can operate effectively even in colder temperatures, electricity prices can also be affected by factors such as generation costs and government policies.

It’s therefore difficult to predict exactly what will happen with energy prices, but over the last 10 years, Sophie has also installed photovoltaic solar panels to reduce her dependence on electricity prices. Once the installation and maintenance costs of these panels are factored in, she has still seen a reduction in her net electricity bills for this specific installation, while Marc’s running costs have been variable and sensitive to fluctuating gas prices.

Energy efficiency of gas boilers and heat pumps

It’s not just a case of the unit price of gas or electricity alone, the energy efficiency of a heating system is also an important metric.

Depending on the model and operating conditions, a heat pump can convert up to 400% of the energy it uses into usable heat, producing around 4kWh of heat for every 1kWh of electricity it consumes, since roughly three-quarters of that heat comes from ambient air, water or ground and only about a quarter is supplied as electricity.

For example, 3kWh is enough to:

• Heat a small room for three to four hours
• Provide two 10-minute hot showers
• Toast 9,000 slices of bread!
• Run two dishwasher or laundry cycles

Modern condensing gas boilers typically operate at much lower efficiencies, ranging from 99-109%.

To generate enough usable heat for two 10-minute hot showers etc, even at the higher efficiency of 109%, your boiler would consume 2.75kWh of gas, rather than the heat pump’s 1kWh.

There are times when a gas boiler can be more economical, such as in particularly cold climates, or during the coldest days of winter, but overall, the superior energy efficiency performance of the heat pump is one of its main advantages.

Because of this higher efficiency, heat pumps can help reduce a household’s energy bills compared with a gas boiler. The actual savings vary widely and depend on the specific models compared, purchase and installation costs, electricity and gas tariffs, climate, and usage patterns so any total savings should be calculated for your specific situation rather than assumed.

The carbon footprint comparison

One of the main drivers of the increased uptake in heat pumps is of course the environmental impact.

Because they provide heating with up to 75% from renewable thermal energy in the air, water or ground, heat pumps have a lower carbon footprint. This footprint can be reduced even further if the remaining 25%, supplied as electricity, comes from solar or wind power.

Boilers rely on burning gas, which releases carbon dioxide (CO₂) emissions. It is estimated that around 2.1 kg of CO₂ is released for every cubic metre of gas used, contributing directly to greenhouse gas emissions.

Conclusion: Assessing the overall return on investment

Overall, a heat pump can represent a worthwhile long-term investment for many households thanks to its longer lifespan, generally lower maintenance costs and higher energy efficiency compared with a gas boiler, though the actual return depends on your specific installation and energy costs. With many countries now offering incentives, a heat pump can be a financially and environmentally appealing choice. So if you're planning to upgrade your heating system, it could be a good time to make the switch.

Key takeaways

The points below compare a modern air-to-water heat pump, like Sophie's, with a traditional condensing gas boiler, like Marc's.

• Heat pumps can help reduce running costs compared with a traditional gas boiler due to higher efficiency than gas boilers.
• Installation cost is higher, but heat pumps last 5-10 years longer and the maintenance cost is lower.
• Gas prices fluctuate significantly, while heat pump costs can also vary due to electricity prices and government policies.
• Heat pumps have a much lower carbon impact, especially when powered by renewable electricity.
• Government grants can help reduce installation costs and improve overall ROI of heat pumps.