If you have a working chimney, you can fit almost anything: a wood burner (usually with a liner), a gas fire or an open fire. Without one, a wood burner needs a twin wall insulated flue; a gas fire can use a balanced flue or power flue through an outside wall, or be a flueless model with the right room size and vent; and electric or bioethanol fires need no flue at all.
Start by working out which flue you have, then choose the fire to suit it. This guide shows how to identify your flue, what each option needs, how they compare on heat, installation and upkeep, and which to choose for your home.
Your options at a glance
| What you have | What you can fit | Key requirement |
|---|---|---|
| Brick chimney (often 175mm or larger) | Wood burner, multi-fuel stove, open fire, cast iron fireplace, most gas fires | Sound flue; often a liner for a stove; sweep and inspection |
| Prefabricated metal flue (often 125mm) | Many gas fires; a stove if the flue is rated for solid fuel | Check the flue's designation |
| Pre-cast block flue (ridge vent on the roof) | Slimline gas fires made for pre-cast flues | Shallow firebox |
| No chimney, outside wall available | Balanced flue or power flue gas fire; wood burner with external twin wall | Wall position and terminal clearances |
| No chimney, internal route possible | Wood burner with internal twin wall flue | Route through ceilings and roof |
| No flue possible | Flueless gas fire, electric fire, bioethanol stove | Room size and ventilation (gas, bioethanol); a socket (electric) |
You have a chimney
A stove on your chimney
Real wood heat, usually with a liner sized to the stove's 125mm or 150mm outlet.
No chimney, real fire
A stove with a twin wall flue
A factory-made insulated chimney through the roof or up an outside wall.
Flame at the touch of a button
Gas fires
Inset fires for chimneys and flues, plus flueless models for rooms with no flue at all.
No flue, no gas
Electric fires
Media wall, inset and wall-mounted fires that plug in or are wired by an electrician.
Real flame, no flue
Bioethanol stoves
Liquid fuel burners with a real flame and modest heat, for larger, well-ventilated rooms.
How to tell which flue you have
- Chimney breast and a chimney stack with a pot: a traditional brick chimney, often called a Class 1 flue, usually at least 175mm (7 inches) across.
- A metal flue or cowl on the roof, no stack: a prefabricated flue, often 125mm (5 inches), called a Class 2 flue.
- A raised ridge vent, no chimney breast: a pre-cast flue made of interlocking blocks, common in houses built from the 1960s onwards. These are shallow and narrow.
- Nothing at all: no flue. You will need a new one, or a fire that needs none.
If in doubt, a HETAS registered installer (for stoves) or Gas Safe registered engineer (for gas) can survey it. A chimney that has not been used for years should be swept and checked before anything is fitted to it.
With a chimney: wood burners and open fires
A brick chimney built for an open fire is usually far wider than a modern stove's 125mm or 150mm outlet, so most installers fit a stainless steel liner sized to the stove. It keeps the flue gases warm and fast, which means a better draught and less tar. Approved Document J allows flexible metal liners for relining an existing chimney. Stoves that are exempt for smoke control areas can generally use a 125mm flue; most others need 150mm.
Check the chimney height and outlet position too; see how tall should my chimney be? A cast iron period fireplace also needs a working chimney, and in a smoke control area an open fire can only burn authorised smokeless fuel.
No chimney: a wood burner with a twin wall flue
A twin wall flue is a factory-made insulated stainless steel chimney. It can run straight up through the house and roof, or out through a wall and up the outside. It must meet the same rules as a masonry chimney: flue height (4.5m can be satisfactory), outlet position on the roof, no more than four bends of up to 45 degrees, clearances to combustibles and sweeping access. Modern homes are airtight, so check the air supply rules too: do I need a vent?
Stoves suited to new builds and extensions include the Carron ECO 5kW, which can take an external air supply, and the compact FDC4 Eco.
Gas fires: conventional, balanced, power flue or flueless
- Conventional flue: uses a chimney or flue. Approved Document J sets minimum flue sizes: 125mm for a radiant or convector fire, and a minimum dimension of 175mm for most inset live fuel effect and decorative fuel effect fires in a standard fireplace opening. The full depth Ekofires 3060 suits a brick chimney or prefabricated flue; the slimline Ekofires 3015 has a 108mm deep firebox that suits pre-cast flues.
- Balanced flue: the fire is sealed from the room and draws air in and sends fumes out through a pipe in an outside wall.
- Power flue: a fan pushes the fumes out through a wall, for rooms where neither a chimney nor a balanced flue will work.
- Flueless: a catalytic converter cleans the combustion products, so there is no flue, but there must be a minimum room size and a permanent vent. The Ekofires 5510 needs a room of at least 27 cubic metres and a 100cm² vent, and gives 1.3kW to 2.3kW.
All gas fires must be installed by a Gas Safe registered engineer, and since 1 October 2022 a carbon monoxide alarm is required in the room when a new or replacement fixed gas appliance (other than a cooker) is installed in a home in England. More detail: gas fire types explained.
No flue at all: electric and bioethanol
Electric fires
Electric fires need no flue or ventilation and suit flats, bedrooms and media walls. Ours give up to about 2kW, enough to take the chill off a room or top up central heating. Our range includes:
- Media wall fires such as the Acantha Aspire 125, 1304mm wide, 1kW or 2kW, with a remote and 7-day timer, built into a stud wall.
- Inset fires such as the Ekofires 1060, up to 2kW, which comes with spacer frames to fit fully inset, semi inset or flat to the wall.
- Wall-mounted fires such as the Sureflame WM-9331, 1066mm wide, 0.9kW or 1.8kW.
- Electric stoves such as the Adam Woodhouse, a freestanding stove look with 0.9kW or 1.8kW of heat.
Hardwired models need an electrician; plug-in models need only a suitable socket.
Bioethanol stoves and fires
Bioethanol burns liquid fuel with a real flame and no flue. It gives modest heat and needs a well-ventilated room: the Adam Bellini gives up to 3kW from a 1.5 litre burner and needs a room of at least 63 cubic metres. Store, fill and light the fuel exactly as the manufacturer says, and never refill a burner while it is hot.
How the options compare
Heat outputs below are from products in our range; check each product page for the exact figures.
| Option | Typical heat (our range) | Who installs it | Ongoing upkeep |
|---|---|---|---|
| Wood or multi-fuel stove | 4kW to 8kW for room heaters | HETAS registered installer, or building control | Chimney sweeping, seals and firebricks, dry logs |
| Inset gas fire on a flue | About 3kW to 4kW | Gas Safe registered engineer | Annual service and safety check |
| Flueless gas fire or stove | About 2kW to 3kW | Gas Safe registered engineer | Annual service; keep the vent clear |
| Electric fire | Up to about 2kW | None for plug-in; electrician if hardwired | Very little |
| Bioethanol stove | Up to about 3kW | None; follow the maker's instructions | Buying and storing fuel safely |
Which should you choose?
- Want real wood heat and the look of a stove: a stove on your chimney, or a twin wall flue if you have none.
- Want flame at the touch of a button with a chimney or outside wall: a gas fire.
- Want a period look: a cast iron fireplace on a working chimney, with an open fire or a matching gas fire.
- No chimney, no outside wall, or renting: electric.
- Want a real flame for occasional use with no flue: bioethanol, in a large enough room.
Browse stoves, flueless fires and media wall fires.
Common questions
Can I have a log burner without a chimney?
Yes. A twin wall insulated flue can run up through the house or out through a wall and up the outside. It must meet Building Regulations for height, outlet position and clearances.
What is the difference between a Class 1 and Class 2 flue?
A Class 1 flue is usually a traditional brick chimney at least 175mm (7 inches) across. A Class 2 flue is usually a prefabricated metal flue of about 125mm (5 inches). Pre-cast block flues are shallower and narrower again.
Can I have a gas fire without a chimney?
Yes: a balanced flue or power flue fire vents through an outside wall, and a flueless fire needs no flue but must have the minimum room size and permanent vent its maker specifies.
What fire can I have in a flat with no chimney?
Usually an electric fire, which needs no flue or ventilation. Flueless gas or bioethanol may be possible if the building, room size and ventilation allow, but check the lease and building rules first.
Do I need a liner for a wood burner in an old chimney?
Usually. Old chimneys built for open fires are much wider than a stove's outlet, so a liner sized to the stove keeps the gases warm and the draught strong. Your installer will assess the chimney.
Do electric fires give out real heat?
Yes. Most of ours give 1.5kW to 2kW, enough to warm a small room or top up central heating, and several have a remote with a 7-day timer.
Is a bioethanol stove safe indoors?
Used as the manufacturer instructs, in a room at least as large as it specifies and with good ventilation. Never refill a hot burner and store the fuel safely away from heat.
Can I fit a gas fire to an old coal fire chimney?
Often yes, provided it is shown to be safe in the gas fire maker's instructions and the chimney is swept and checked. A Gas Safe registered engineer will test the flue before fitting.
Not sure what your home can take?
Send us a photo of your fireplace and of the roof outside and we will tell you which of our stoves and fires could suit it.
