Heat pumps vs gas boilers 2024 comparison guide

Gas boilers have done a great job of keeping Britain warm for decades. Compared to traditional open fires, they’re amazingly clean, convenient and cheap to run.

But with more and more of us concerned about carbon footprints, a new and greener option has recently made a welcome entrance – the heat pump.

In this guide, we’ll look at the main differences between heat pumps and gas boilers, to help you work out which is the best choice for your home.

What are the main differences between a heat pump and a gas boiler?

Heat pumps and gas boilers both do essentially the same thing – they use energy to supply hot water and heating for your home, all year round. But the way they do that is very different.

How do gas boilers work?

Gas is burned inside the boiler to heat water, which is then stored in your tank. Or if you have a combi boiler, water is heated on demand and sent directly wherever it’s needed.

The advantages of gas boilers include:

  • Affordable
  • Easy to install
  • Reliable

How do heat pumps work?

Heat pumps run on electricity. They take warmth from the outside air, then compress it to raise the temperature. This heats water that’s stored in your tank and used around the home. (link within here to the heat pump system guide)

The advantages of heat pumps include:

  • Lower carbon
  • More energy efficient
  • Long lifespan of 20+ years

Key facts

Gas boilers

Heat pumps

Powered by
Powered by Natural gas Electricity
Cost From £2,750 From £499 including £7,500 grant
Potential energy savings 1
Potential energy savings 1 Up to £415 a year Up to £385 a year
Efficiency At least 90% Up to 380%
Carbon High Low
Installation One day One week
Lifespan 10-15 years 20+ years
British Gas warranty
British Gas warranty Up to 12 years' 5 years

Find your new boiler Go green with a heat pump

How does a heat pump replace a gas boiler?

However, lots of people are already choosing to upgrade their gas boilers to heat pumps. At British Gas, we do this every day, up and down the country. Here’s what’s typically involved in one of our installation projects:

Step 1: survey

An expert visits your home to look at all the factors that affect your heating system. For example, how big your property is, how well insulated it is and how many people live there.

Once our surveyors have looked at everything, we can recommend the right size heat pump for you, plus any changes that might be needed to your home, such as bigger radiators or wider pipework.

Step 2: installation

Installing a heat pump is a bit more complex than installing a gas boiler. A new boiler might only take a day, but upgrading to a heat pump usually takes about a week.

There’s some disruption to your home during this time, but at British Gas we do everything we can to keep this to a minimum.

Are heat pumps cheaper than gas boilers?

This varies by property, but heat pumps usually cost a bit more than gas boilers. Sometimes the government grants can make heat pumps cheaper than boilers though.

How much do boilers cost?

You can expect to pay anything between £2,750 and £5,000 for a new gas boiler.

The price depends mainly on the size, or how powerful it is. Installation also costs more if you’re changing the type of boiler – for example, replacing a conventional boiler with a combi. And it costs more if you move the boiler to a different part of your home.

How much do heat pumps cost?

The £7,500 government grants help make heat pumps more affordable than they otherwise would be.

If you don’t need much extra work to your home – like extra insulation or new radiators – you can pay as little as £500 for a heat pump with British Gas.

Most homes do need some work though. From October 2023 to February 2024, our average price (after the grants were applied) was £4,415.

Running costs: air source heat pumps vs gas boilers

You can get the full details on running costs in our heat pump costs guide.

But the short answer to the question is: if your home is well insulated, you’ll probably pay about the same or slightly less to run a heat pump instead of a gas boiler.

Although heat pumps are more efficient than gas boilers, electricity is currently around four times more expensive per unit than gas. So the improved efficiency doesn’t directly translate into financial savings.

Want to see how much a heat pump might cost to run in your home? Try our handy calculator.

Are heat pumps as good as boilers?

There’s no simple answer to this question. Boilers and heat pumps both have pros and cons to consider. Here’s a quick rundown of the main things to be aware of.

Heat pumps vs boilers: which is most comfortable?

Boilers and heat pumps generate different kinds of heat. Boilers are designed to provide quick bursts of high heat (between 70°C and 80°C), whereas heat pumps provide steadier supplies of lower heat (35°C and 55°C).

That’s why good insulation is so important with heat pumps. Gas boilers are good at keeping you comfortable even if your home loses heat quickly – although that does mean higher bills! But heat pumps need low levels of heat loss to create a comfortable ambient temperature.

So both are excellent at keeping your home comfortable, but heat pumps really do need good insulation to work at their best.

Heat pumps vs boilers: which is greener?

Heat pumps are one of the lowest-carbon ways of heating your home. They are powered by electricity, so they’re as low carbon as your electricity supply. According to the National Grid, 38.2% of UK electricity was generated from renewable sources in 2023.

As the electricity supply gets greener, so will heat pumps. That’s why generous grants are available for people to make the switch away from gas boilers. The government sees them as an important way for the country to hit its target of achieving net zero by 2050.

And if you’re serious about getting your carbon footprint as small as possible, combining a heat pump with solar panels is a great idea. You can generate your own zero-carbon electricity to directly power your heat pump!

Heat pumps vs boilers: which is easier to use?

Smart thermostats like Hive make modern boilers very easy to control. Just open the app on your phone to raise or lower the temperature, set schedules, or get info about your energy use.

Heat pumps are just as easy to manage. Just use the controls to set target temperatures and make any other changes you want.

Heat pumps vs boilers: which is most reliable?

British Gas recommends getting your boiler serviced every year to keep it running safely and efficiently.

If you do this, you can normally expect your boiler to last for around 15 years. You might experience some problems or breakdowns in that time, but it’s easy to arrange a boiler repair or even take out HomeCare cover for total peace of mind.

Heat pumps are just as reliable as gas boilers.

The technology they use is quite simple, so they won’t need much maintenance beyond an annual service by an engineer. And the average lifespan is even longer than for a boiler. A heat pump you install today should still be working perfectly well in 20 years’ time.