Gas fires are a popular choice for many, offering the style of a traditional fireplace with the convenience of a readily available mains fuel supply. They don’t have to be purchased in a traditional style, though, as modern designs are also available. Find a great choice of gas fires and stoves available to purchase from Thornwood Fireplaces. This guide aims to help to understand the different options available when purchasing a gas fire and what to look for in the product description.

Types of Gas Fire

There are lots of different types of gas fire; the choice is huge. In terms of how the fire is positioned in the fireplace or in the room, the following options are available.





Wall mountedPlaced completely into the wall, at whatever height requiredSuitable for rooms without flue or chimney Usually found in more modern designsMay not suit more traditional homes Could cost more to fit
InsetAt the bottom of a fireplace, set into the wallFit well into an old fireplace – either from an old inset fire or previous ‘real’ fireCan only buy a fire which fits the dimensions of the fireplace void
OutsetNot set into the wall at all, can be mounted to the wall to keep secureCan be fitted to rooms where there has not previously been a fireplace, or it has been removed from the room in the pastTakes up space in the room
Stand alone stoveOften made to look like a traditional wood burning stoveUseful if want to place fire away from the wallMay dominate a room Limited range of styles

Chimneys and Flues

Before buying a new gas fire, it is important to check the chimney in the room that the fire will be situated. In particular, the type of flue will determine which gas fires will be able to be fitted. The flue is the part of the chimney that vents exhausts gases from the fire to outside. In the past, having no chimney meant that a gas fire could not be installed. This is not now the case, with a range of gas fires available for chimneyless homes. To work out the flue and chimney type, go outside and check what the chimney looks like on the roof.

Brick chimney

Chimney stacks on the roofClass 1Usually found in traditional chimneys, which have had coal fires in the past. Usually 7 inches in diameterAll gas fires, these are the most versatile flue types and are effective at venting even powerful fires


Metal pipe coming out of the roofClass 2Similar to Class 2, but usually 5 inches in diameterMost gas fires will be suitable as same air circulation should be available as with a brick chimney


Raised rectangular section coming out of roof tilesPre-castUsually found in modern homes, the flues tend to be shallowSlimmer gas fires or use a spacer kit to fit a deeper fire

No chimney

Some homes don’t have any kind of chimney, this means no flue on the roofNoneNone – Additional room ventilation requiredFlueless fires
BalancedInstalled against an outside wallGlass fronted gas fire Tend to have low running costs and good heat output
Powered flueExpels waste gases using an electric fan (may be noisy)Open fronted gas fires

Other Factors to Consider when Buying a Gas Fire

Consider the following factors when selecting a gas fire.


Before buying a new gas fire, it is important to be aware of the measurements of the area where the fire is to be fitted. If fitting in an old fireplace or to fit with an existing fire surround, make sure accurate measurements have been taken before looking at a new fire. One benefit to buying on eBay is that there is plenty of time to browse and check the product description before purchase. Consider marking out the dimensions of the possible new fire on the wall with masking tape before purchase, in order to see more clearly how it will look in the room.

Heat Output

The heat output of a gas fire will be measured in kilowatts (kW). This indicates the amount of heat that will be given out to the room by the fire. Heat outputs are often between 3 and 5 kilowatts for domestic gas fires. In general, for larger rooms, a higher heat output will be needed to heat the room effectively. For a smaller room, a lower heat output will suffice. It also depends on whether the gas fire will be used as the only heat source, or alongside central heating. If the fire is only to add a little extra heat in a centrally heated home, then a low heat output could well be appropriate, even for a larger room. Another factor to bear in mind is the insulation level of the house, in particular of the room in which the fire will be situated. A double glazed room is likely to retain heat better than a room with single glazed windows. If the house is well insulated, a lower heat output fire may be fine in a larger room, but in a poorly insulated home, a more powerful fire could be necessary. If the room has an open staircase leading out of it, or is a through room, the heat output may need to be high, to counteract the loss of heat into other spaces in the house.

Fuel Efficiency

One good reason for buying a new fire is to improve fuel efficiency. Older gas fires may well be less efficient, some offering as little as 15 per cent fuel efficiency. This means a high gas bill without getting much heat from the fire. New fires can offer up to 90 per cent fuel efficiency. This means that 90 per cent of the energy that goes into the gas fire will be turned into effective heat. When replacing an old inefficient fire with a new greener efficient gas fire, then energy bills should be lowered overall. It is often the glass fronted fires which will offer the highest fuel efficiency. If keeping ongoing fuel bills down is a priority, then this may be the best type of gas fire to buy. Flueless gas fires lose no heat through the chimney, meaning a high fuel efficiency. The efficiency rating of the fire will often be included in the description of the item.

Type of Control

Traditionally gas fires have been fitted with a manual control, either a dial or a switch. Rotary control, i.e. a round dial, is often still found on gas fires. Modern gas fires are now often available with a remote control. This offers great convenience, meaning turning the fire on and off without having to leave the seat is now possible. Another popular option is to have a slide control. This usually means that there is a slideable control on the top of the fire, avoiding the need to get down on hands and knees to turn the fire on and off, or to adjust the heat. Slide control may be described as Top Control or Fingerslide, depending on the manufacturer or seller. Top control or remote control gas fires are a useful option for the less agile or the elderly, finding it difficult to kneel down to operate the fire.

Fitting a New Gas Fire

Gas appliances must be fitted by a GAS SAFE registered engineer. The engineer will ensure that the fire is fitted safely and with suitable ventilation. It is important not to try to fit a gas fire without using an engineer. If a gas fire has previously been fitted in a room, there is likely to already be a suitable gas source and ventilation, which may make the fitting costs lower.


Gas fires can be found to suit almost any home. Whether maintaining a traditional look with coal or wood effect, or going for a more modern wall mounted flame only effect, a gas fire can add warmth and character to the room. Use the guide to help choose the right gas fire for the home and enjoy the fire’s warmth and character. Contact us for further information or to arrange a home visit.