Heat pump vs gas boiler

When the time comes to invest in a new heating and hot water system there are many things to think about.

You need to consider your budget, timescales, the infrastructure you already have in your home, running costs and the environmental impact of your choices. 

Differences between gas boilers and heat pumps 

Aside from burning natural gas or oil, there are a few key differences between boilers and heat pumps.


One of the large differences between gas boilers and heat pumps is the temperatures that they produce. 

Boilers are designed to be used for short periods and produce a lot of heat to warm your home quickly. 

Heat pumps however are designed to heat your home more slowly due to their set-up. They have a lower flow temperature and increase the heat slowly within the home and so work well with large radiators or underfloor heating. 

Here is why you might not need to replace radiators in your home to install a heat pump.

Both oil boilers and heat pumps create heat in your heating system meaning the output is the same – giving you a warm home, however, the difference lies in the way and speed that they both do it. 

How much do heat pumps cost compared to gas boilers? 

The cost of all the different heating systems will depend on the size of the property and whether you are replacing an existing system or if you are having a completely new heating system added.

Gas boiler: Gas boiler prices will generally be between £1,500 and £3,500. This will include gas boiler installation. 

Air Source heat pump prices: The cost of an air source heat pump is normally between £7,000 to £13,000 according to the energy saving trust.

Ground source heat pump prices: A ground source heat pump generally costs between £14,000 and £19,000 according to the energy saving trust.

Ground source heat pumps have greater initial installation costs as there is a lot of preparation work that needs to be done outside of the property to install the underground pipes. However, they are often the most cost effective in the long term.

It is worth remembering that even though new gas boilers may have a lower upfront cost, it is likely that you would save on your energy bills going forward by installing a heat pump as they are more energy efficient than a new gas boiler. 

Are heat pumps cheaper to run than gas boilers?

One of the main reasons people want to compare pumps vs gas boilers is to see if a heat pump would save money on energy bills.

The running cost of a heat pump vs gas boiler depends on how it is running.

If you are looking to get a new central heating system installed and are wondering whether a heat pump will save you money on your energy bills compared to a gas boiler, it will depend on the system that the heat pump would be replacing.

Air source heat pump savings vs boilers: The amount you will save will vary dramatically depending on the system you are replacing. According to energy saving trust, heat pump installations to replace Old (Grated) LPG boilers could save you around £3,400 a year and you could save £1,400 a year on new A-rated LPG boilers.

Ground source heat pumps savings vs gas boilers: According to the energy saving trust, installing a ground source heat pump to replace Old (Grated) LPG boilers could save you around £3,600 a year and you could save £1,500 a year on new A-rated LPG boilers.

Is heat pump installation the same as getting a gas boiler installed?

The time it takes to get either a heat pump or a boiler installed will depend on the heating system you currently have in your home.

How long does a gas boiler take to install? Gas boilers can take anywhere between 1-3 days depending on where you are having it fitted.

If you are simply installing a new gas boiler in the same position as an existing gas network then it will likely only take one day. However, if you are moving your boiler to a different location it will likely take longer.

How long do air source heat pumps take to install? An air source heat pump system will generally take between 1 – 5 days to install on your property if you are replacing a gas or oil boiler.

How long do ground source heat pumps take to install?

Ground source heat pumps will generally take around a week from start to finish to install. The ground source heat pumps unit could be installed in as little as a day, however, the preparation for underground pipes and their installation is likely to take a few days.

Do Heat pumps take up more space than gas boilers?

When it comes to saving space, heat pumps vs gas boilers are pretty similar in size.

Gas boiler: gas boilers are generally pretty compact and are often tucked away in a kitchen cupboard, utility room or loft to save space.

Air source heat pump: Air source heat pumps can be great for space-saving as the main unit for the heat pump is installed outside of your home. Having your heating system on the outside of the property is a great way to free up some cupboard space internally.

Ground source heat pumps: Although ground source heat pumps need a lot of space to install the pipework, once this is installed a ground source heat pump is normally similar in size to a generic boiler.

Do heat pumps have a lower carbon footprint than gas boilers?

If you are looking for a low carbon heating system, then a heat pump is likely to be a good option in comparison to fossil fuel heating systems.

Both boilers and heat pumps need electricity to run, however, due to many energy providers now offering renewable energy tariffs, it is possible to reduce the amount of carbon dioxide produced even further.

Gas boiler carbon emissions: You can expect a modern A-rated gas boiler to emit 215 grams of CO2 per kWh of heat produced.

A condensing boiler is likely to be more eco friendly than a noncondensing boiler.

Heat pump carbon emissions:  Heat pumps are considered low carbon heating systems as they burn no fossil fuels. They are powered only via electricity, and if you choose a renewable energy tariff, your heat pump could provide a completely renewable, carbon neutral, heating system.

Do heat pumps need more maintenance than a gas boiler?

The maintenance for a heat pump vs gas boiler is generally pretty similar.

Gas boiler maintenance: It is recommended that the average boiler is serviced every year by an engineer on the gas safe register.

Heat pump maintenance: Heat pumps should be serviced annually and most heat pumps come with a two or three year warranty.

Do you need to replace heat pumps more regularly than gas boilers?

If a heat pump is well maintained it will likely outlast even modern boilers.

How long does a gas boiler last? The average gas boiler is expected to last between 10 and 15 years.

How long do heat pumps last? If well maintained a heat pump can last for 20 years or more.

How many homes have gas boilers v heat pumps in the UK? 

In the UK, the vast majority of residential properties use a gas boiler with 85% of homes (or 23 million) connected to the gas grid. 

The 15% of homes in the UK that aren’t connected to gas generally use either oil or liquid petroleum gas as the main source of fuel for their heating needs. 

Of the 29 million homes in the UK less than 250,000 currently have heat pumps, however, this is expected to rise rapidly over the coming years. The government have set out plans to install 600,000 heat pumps per year by 2028. 

Are boilers being phased out in the UK?

Yes, to reduce the UK’s carbon emissions the government announced that it would be introducing measures to ban gas boilers. 

The measures the UK government are introducing include: 

  • Banning the installation of any gas boilers into new properties from 2025 
  • Phasing out the installation of any gas boilers in any property by 2035

These measures are all part of the government’s plan to help it reach its goal of hitting net zero carbon emissions by 2050. 

Although the government has announced these measures, there is no guarantee that they will be brought into force. However, gas boilers will likely begin to be phased out in the UK and installation of renewable heating systems will be prioritised.