How to Buy a Used Gas Fire

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How to Buy a Used Gas Fire

Gas fires are a fantastic way to introduce warmth and character into a property. They can provide an effective source of heating and also look great. Which type of gas fire is suitable will depend upon factors such as flue provision, the amount and type of heat required, budget and appearance. When buying a used gas fire there are certain safety considerations to bear in mind. Gas fires should come with installation instructions, meet current safety standards and should always be installed by a Gas Safe registered installer.

Choosing a Used Gas Fire

The various styles of gas fire include inset fires, wall mounted fires, and outset fires. Some fires do not require a chimney, such as balanced flue and powered flue fires. Flueless gas fires do not require a flue of any type. The depth of fuel bed also needs to be considered. Consult a qualified Gas Safe registered installer if there is any doubt as to the suitability of a particular gas fire.

Type of Flue

Class 1 Chimney

Class 1 flues are traditional brick built chimneys. They are 7”, 9” or more in diameter. Emissions are vented straight up the chimney. This type of flue is suitable for most gas fires, including deep fuel bed fires.

Class 2 Chimney

Class 2 flues are pre-fabricated flues that usually have a metal roof terminal. They are 5” or more in diameter. This type of flue is suitable for slimline fuel bed gas fires.

Pre-cast Flue

Pre-cast flues are hollow concrete or clay blocks installed in cavity walls with a roof vent. This type of flue is suitable for a smaller range of fires.

Balanced Flue

Balanced flue gas fires require a flue that is vented directly through an external wall. The flue consists of an outer and inner pipe, with air entering through the outer and emissions exiting through the inner. The fires require a glass front.

Powered Flue

Powered flue gas fires also require a flue vented directly through an external wall. The flue is driven by an electric powered fan assembly, with safety sensors that shut off the fire in case of failure. They require a minimum 2 m clearance as well as an electricity supply and can be noisy. The fires do not require a glass front.


Flueless gas fires do not require a flue and emissions are vented back into the room. They can be installed on external or internal walls. The most common type has a catalytic converter to convert carbon monoxide into carbon dioxide and water. Flueless gas fires require a minimum room size, an air vent fitted to an external wall and the room to have a window that can be opened.

Radiant and Convected Heat

There are two basic types of heat that gas fires can provide. The first is radiant heat which is heat concentrated in the area around the fire. This is the type of heat provided by a real open fire. The second is convected heat which is heat dispersed evenly around the room.

Gas Fire Styles

Deciding on an appropriate style of gas fire is determined by a variety of factors, not least being personal taste. Knowing what the possible options are, however, greatly helps in this matter.

Inset Gas Fires

Inset gas fires are placed into recessed fireplaces. They usually fit flush to the fireplace. Conventional inset gas fires require a chimney or a natural draft flue, with certain models only appropriate for certain flues. Inset fires can provide radiant heat, convected heat, or both. Balanced flue and powered flue gas fires are also available in inset designs. These types of gas fire do not require a chimney or existing natural draft flue. They are installed either recessed into an external wall or against the internal surface. If surface fitted, a fire surround or fake chimney breast will also need to be installed. The flue vents through the external wall. Flueless gas fires are also available as inset fires. Inset fires come in a variety of both traditional and contemporary styles. They can be used to either replace old fires or be combined with new surrounds. They are a superb option if the appearance of a real fire is desired and often come with coal bed or log effects and natural looking flames. Traditional styled inset fires work well with period properties and traditional decor. They are usually sized to fit a standard sized fireplace opening at around 56 cm height and 40 cm width. Cast iron, black, brass, and marble surrounds are popular, along with black or marbled interiors. Contemporary styled inset fires work well in any type of property and work especially well with modern interiors. Popular surrounds include brushed or polished chrome or steel and natural stone. Some inset fires have glass fronts. These increase energy efficiency and can be removed for maintenance. They can get hot so care should be taken just as with fires without glass fronts.

Outset Gas Fires

Outset gas fires are placed within fireplaces, upon hearths or fixed to walls. They project into the room. They can be used with most flues, with fires available in both balanced flue and powered flue designs. They can provide both radiant and convected heat and some models have high level switches. They are open fronted. Outset gas fires come in both traditional and contemporary designs, though many lean towards the more traditional. Some feature wood surrounds.

Wall Mounted Gas Fire

Wall mounted gas fires are mounted onto walls, either external or internal. They do not require a flue. They usually have glass fronts and are energy efficient. Heat levels are usually easily controllable. Wall mounted fires have a smart, contemporary appearance and can make for stunning focal points. They are available in a variety of shapes, sizes, and styles, making them suitable for even quite small rooms. Typical materials include brushed and polished chrome, stainless steel, polished black glass, and natural stone. Interiors are often black while some models have reflective interiors. They have a variety of different flame effects, from small ribbon flames to dramatic torch flames.

Freestanding Gas Fires

Freestanding gas fires can be used with most flue types, depending on the model. They are placed upon a hearth, projecting into the room. They are efficient with good heat output and have glass fronts. Freestanding gas fires usually have a traditional appearance, like that of a stove or wood burner, and are made of materials such as cast iron and cast aluminium. They often have coal or log fuel bed effects and realistic looking flames.

Buying and Installing a Used Gas Fire

All gas fires need to be installed by a Gas Safe registered engineer. Caution should be taken with used gas fires. They should be sold with the installation instructions and should have a dataplate. Used gas fires should also meet current safety regulations and installation tests. All the parts should be included and fires should be fully functional.


Used gas fires are available in a variety of different types and styles. The types that can be installed will depend primarily on the type of flue. Class 1 flues are the most versatile, and Class 2 flues and pre-cast flues are suitable for a smaller range of fires. Balanced flue and powered flue gas fires vent directly through an external wall and flueless gas fires do not need a flue. The basic styles are inset, outset, wall mounted and freestanding, with all available in traditional and contemporary designs. Used gas fires should be installed by a Gas Safe registered installer and should meet current safety regulations. Always read product descriptions carefully to be sure of the suitability of a particular fire and if in doubt consult an expert.

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