A flue is a duct or channel for conveying heat – ensuring that smoke and waste products produced by a gas fire or heater are directed safely to the outdoors. The ductwork that runs from the firebox to the top of the chimney draws the lighter exhaust gases and ash through the flue and away.

So, what is a flueless gas fire? Read on…

Flueless Gas Fire Facts

A flueless gas fire doesn’t have a flue! And it operates without any pipes or a chimney. Emissions from the fire leave from a vent at the front or the top. And the fuel is burned very cleanly.

Flueless appliances need additional purpose ventilation provided at a high and low level. And condensation is prevented by keeping the background temperature of the room at an ambient level with central heating.

They’re relatively simple to install – you’ll simply need to contact a Gas Safe registered engineer. And any servicing costs are less expensive as they don’t need the use of a chimney or flue.

Key features include a real gas flame, 100% efficiency, and very little building work needed for installation.

Flueless Gas Fire Workings

How do flueless gas fires work? By drawing clean air in from your room through a front vent the air then passes through a heat exchanger. This creates warm convected air which is then released into the room providing extra heat.

Part of the air taken from the room will feed the gas flame in the fireplace following the combustion process. Alongside the working gas supply, you’ll need a minimum room size of around 30 cubic metres – and the correct size air vent.

The catalytic converter which converts carbon monoxide into harmless gases works so effectively that it can help to neutralise airborne particles and odours reducing allergies.

Flueless Gas Fire Safety

Are flueless gas fires safe? The gases produced and passed through a catalytic converter are safe as the filter changes any harmful emissions to safe gasses before releasing them. You’ll just need to have the appliance serviced each year by a Gas Safe engineer.

Make sure the fitted vents are never obstructed. It’s advisable to fit a carbon monoxide alarm in the same room. And safety measures will automatically shut the gas supply off if there isn’t a sufficient supply of clean air.

Flueless Gas Fire

Flueless Gas Fire Advantages and Disadvantages

Flueless gas fires pros and cons are outlined below:


  • Low running costs – gas is cheaper than electricity and can cost from as little as 9p per hour for a 2kw flueless fire;
  • Inexpensive to install – the cost is so much cheaper as there are no chimneys or flue pipes to consider;
  • Greater efficiency – as no heat is lost via the chimney flueless fires are 100% efficient, and catalytic converts can last for up to 28 years;
  • Wide-ranging choice of designs – varying from wall mounted to built-in options;
  • Reliability – flueless fires are one of the safest options and are extremely dependable due to stringent CE regulations;
  • Limitless location – flueless fires can be fitted on internal or external walls;
  • Safety features – a safety device will automatically shut off the fire in the event of an air blockage or other potential risks;
  • Eco-friendly – flueless technology has been awarded five stars for eco value for money – and by making a real contribution towards reducing global warming and lowering gas bills.


  • Room specifics – your room needs to measure at least 30 cubic metres for your flueless fire to be safely installed, and needs a window that opens to the outside;
  • Other heat sources needed – you must have radiators or another heat source as the flueless fire can’t be the primary heating supply;
  • Lesser heat output – flueless fires give out less heat;
  • Air vent required – a good quality air vent will need to be fitted from the room to the outside;
  • Screen discolouration – glass screens can discolour and can become extremely hot – flueless fires with catalytic converters that lower emissions need a glass front;

Flueless Gas Fire Complications

Flueless gas fires problems may include low-cost air vents that can cause noise or draft issues. And they can’t be installed in small rooms as there is insufficient air to burn. Any advice you need with regards to installing a flueless gas fire can be given by professionals from trusted fireplace installation services.