How to buy the best gas fireplace

Gas fires offer an efficient and convenient alternative to wood burning stoves. 

They can generate a lot of heat, and gas is much cheaper than electricity. However, they can be a bit tricky to set up and maintain. 

Not only that, you should consider the health and environmental impacts of burning fossil fuels for heat.  

Our guide covers everything from buying a gas stove, to servicing and maintenance. 

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Gas fireplace ideas

Click through our gallery to see some of the main types of gas stove. 

There are three key variables which differentiate between types of gas fires: 

• Inset vs outset: Inset models sit inside your fireplace, or even in a hole in the wall, while outset models sit on the hearth or are wall-mounted. 
• Glass vs open-fronted: Glass models sit behind a fixed panel. They are typically a little more efficient than open-fronted fires, but they require some cleaning. 
• Fuel bed: This is what appears to be burning when the fire is on. They include logs, coal or stones. 

Gas fire flue types

Gas fires come with different types of flues – the type you choose will depend on whether or not you have a chimney. 

If you do have a chimney, you can choose a gas stove with a conventional flue. 

If you don't, you can choose a stove with a balanced flue or a flueless model. 

• Balanced flues are designed for homes without a traditional chimney. They come with their own flues that are vented through an external wall.
• Flueless gas fires do not require a chimney or external wall vent. They use a catalytic converter to clean the combustion gases before releasing them back into the room.

If you're considering other options, check out our guide to how to buy an electric stove

Efficiency of gas fires

Some gas fires are more efficient than others – it depends on the flue type. 

Flueless and balanced flue gas fires and stoves can provide heat efficiencies of up to 90%, according to the Heating and Hotwater Industry Council. This means they convert 90% of the fuel into usable heat. 

However, flueless models tend to be less powerful than other options. This is so that they do not generate a large quantity of combustion gases, which can't be expelled outdoors.  

Fires with conventional flues are much less efficient because of the unsealed flue – a lot of heat is lost up the chimney. They run at around 50-70% efficiency. 

Gas fire vs central heating 

The efficiency of your radiators is determined by the efficiency of your boiler. Ultra-modern boilers can also run at up to 90% efficiency.

However, it is important to remember that central heating covers your whole house. Unless your central heating is zoned (so you can control the temperature of different rooms individually), a gas fire will be much more efficient for heating one room. 

Gas fire heat output

The output of a stove is measured in kilowatts (kW). Approximately speaking, to make your room 21°C when it’s 1°C outside, you’ll need 1kW of heat output for every 14 cubic metres of space.

As a rough guide, multiply the height, width and length of your room in metres to calculate the size of your room in cubic metres. Then divide this by 14 to calculate the kWs you will need. 

Note that this is only a rough figure for an average home. Other factors can affect the output you’ll need, such as the level of insulation in your home and the number and size of any windows in the room.

Consult an installer or retailer for more tailored advice about what suits your property.

Are gas fires safe?

Burning gas produces poisonous chemicals, including nitrogen, carbon dioxide, and carbon monoxide. They can irritate your throat, eyes and lungs. In high quantities, they can be fatal. 

However, if properly installed in a well ventilated room, these chemicals are either pumped outdoors or cleaned inside the unit (depending on the type of stove you own). In addition, modern gas fires produce less of these chemicals during combustion. 

If your gas fire is properly installed and maintained, it will be almost completely safe. 

Monitoring your gas fire

If you live in Scotland, you are legally required to have a carbon monoxide dector in the room with your gas fire. In the rest of the UK it is highly recommended. 

Carbon monoxide is tastless and does not have a scent, so you will not know if your gas fire is releasing carbon monoxide into your room. However, this gas is very poisonous and can be fatal. 

You could also consider purchasing a gas fire with an oxygen depletion sensor. These automatically switch off the gas supply if oxygen levels drop, to avoid producing dangerous levels of carbon monoxide.

Are gas fires bad for the environment?

Yes, the poisonous gases produced by gas fires are bad for the environment. 

They are also known as greenhouse gases, which contribute significantly to global warming. 

In addition, the process of extracting gas from the ground  is highly energy intensive and disruptive to the natural environment. 

Read our expert reviews of the best carbon monoxide detectors to find out which carbon monoxide alarms passed our safety tests.

Gas fire unit cost

To find out more about how much real owners typically spend on their gas fire (and how satisfied they are), we asked 39 Which? readers who bought an gas stove in the last 5 years to tell us more about their experience.  

Log in or join Which? to see how much they report spending on their gas fireplace unit.

Gas fire installation

In the UK, all gas products must be installed by Gas Safe registered engineers. 

The engineer should also check that the chimney, flue or vent system you’ll be using is suitable.

Use Which? Trusted Traders to find Gas Safe engineers who have passed our rigorous assessment process and follow our code of conduct.

Gas fire installation cost

The cost of installing a gas fire varies massively depending on the type of fire you install. 

Balanced flue stoves, which require a hole through an external wall, are most expensive. The cost of installation will also increase if you do not have an existing hearth. 

Log in or join Which? to see how much our readers report spending on installing their stove. 

Gas fire running costs

To calculate a very rough running cost for a gas fire, you need to multiply the output in kWs by the price of gas in kWs. 

For example, between October and December 2024, the Ofgem gas price cap is 6p per kW. So it would cost 30p to run a 5kW gas stove for an hour at full power. 

However, this assumes your stove is running at full efficiency – which is not possible.  

If your stove is running at 90% efficiency, you will need roughly 10% more fuel to make it run at full power. 

You can calculate the running cost by dividing the output in kW by the efficiency of the stove – to create the input required in kW – and multiplying this by the gas price. 

Here are some running costs for different stove efficiencies for a 5kW stove. 

To get a better sense of how much it costs to use an gas fireplace, we asked our readers if they feel their fire is too expensive to run. 

We also asked whether or not they use their heating less since having the fire installed. 

Log in or join Which? to see what they said.  

Gas fire servicing

As with all gas appliances, you should get a qualified Gas Safe engineer to check your fire or stove every year to make sure it’s safe to use. You should factor this into your consideration of running costs. 

If you’re using a chimney or flue, you also need to get it cleaned regularly to make sure it’s kept clear of blockages.

You should schedule one of these cleans to take place in late summer or early autumn before you first start using your fire or stove.

See the pros and cons of different stoves in our gas, electric and wood stove comparison

Are gas fires worth it?

To find out if gas fireplaces owners feel their stoves are worth the price, we asked 39 Which? readers who own a gas stove if they are satisfied with their purchase. 

Log in or join Which? to see the percentage of our readers who are satisfied (and dissatisfied) with their stoves.

Gas fire FAQs

Are gas fires being phased out?

The UK government does not have any plans to phase out gas fires. 

However, it is phasing out the installation of gas and oil boilers - indicating a general shift away from burning fossil fuels to produce energy. 

Do gas fires need a chimney?

No, gas fires do not need a chimney.  

You can now buy flueless gas fires, which do not need any external connection. You can also buy balanced flue systems, which only need a hole through an external wall. 

Can I hang a TV above a gas fireplace?

If possible, you shouldn't install a TV above a gas fire. This is because the heat can damage your TV. 

It might be possible to do so, provided your stove isn't too powerful and your TV is far enough away from the unit. 

You should consult with the engineer installing your stove before you add a TV above it. 

Another option – albeit a less aesthetically pleasing one – is to buy a portable electric heater. Check out our reviews of the best electric heaters.