When considering fireplace efficiency you need to consider the appliance type and the fuel you will use to figure out the best gas fire for you. Most high efficiency gas fires use glass on the front to stop heat escaping from the room up the chimney or flue system, including our range of inset gas fires. The alternative is a flueless gas fire, a bio ethanol fireplace or an electric fire all of which are 100% efficient. The difference is that gas is 70% cheaper per Kw than electric or bio ethanol.

To compare the true running costs of different types of gas fire you need to compare them “like for like” using the “input kw rating” of the appliance and the efficiency rating. The table below summaries the different types of gas fires available and compares them with the same heat input to find out the best UK gas fires.

The heat input rating (Kw) of the appliance is the “running cost”.
The efficiency rating of the appliance decides how much of the heat you pay for ends up in the room.

Example Appliance
Efficiency Rating
Heat Input
Heat that comes into Room
Running Cost per Hour
Annual Cost
Flueless Gas Fire
High Efficiency Gas Fire
Balanced Flue Gas Fire
Electric Fire
Bio-Ethanol Fire

Most Cost Effective Fuel Types

So, what are the most budget friendly options if you're looking at different types of fuel to supplement your central heating?

  • Gas @ 4.5p per Kw/Hr
  • Electric @ 13.8p per Kw/Hr
  • Bio-Ethanol @ 275p per Litre
  • Annual Cost is based on 3 hours per night for 120 days (4 months).

The most cost effective way to add extra heat is to use gas. If you need 4kW or less heat you should choose a flueless gas fire, if you need more than 4kW of heat then you should choose a balanced flue gas fire. The amount of heat you require depends on the size of the room and how well insulated your house is. If you’re unsure then please call us and we can help advise you on the best solution. To give you an idea of what 4kW is like, imagine a room with two extra radiators.


Read happy reviews from customers who think efficiency matters when you're looking for the best gas fires in the UK

What is Energy Efficiency?

Are you looking for energy efficiency to save money on your heating bills or to get more heat into your room? Whatever your reason, understanding energy efficiency is an important step towards choosing the best gas fire for your home.

Energy Efficiency is not just about the efficiency rating of the fire. There are other factors that need to be taken into account. The most energy efficient product you can buy today will use gas and will either be a flueless gas fire that doesn’t need a chimney, or a high efficiency inset gas fire which uses an existing chimney and upgrades it to high efficiency or a balanced flue gas fire which need a special flue system. All other forms of heating may provide heat but will cost you more for that heat. It’s an established fact that gas is the cheapest fuel per Kw of heat.

Here’s a couple of examples of how you can save money and keep or even improve heat into the room!

If you have a 6kw open flame fire this will cost you 27p/hour to run and provide 1.5kw of heat into your room. If you replace this with a CVO high efficiency fire like the Bailey it will only cost you 9p/hour to run and still give you 1.5kw into the room. That’s a saving of 67% on running costs. This is because the Bailey has a 2kw burner and is glass fronted with 77% efficiency.
If you have a 6kw open flame fire this will cost you 27p/hour to run and provide 1.5kw of heat into your room. If you replace this with a CVO high efficiency wall mounted fire like the Blade it will only cost you 21p/hour to run but will give you 3.9kw of heat into the room. That’s an additional 150% of heat with 22% less cost. This is because the Blade has a 4.6kw burner and is glass fronted with 84% efficiency.

Best Gas Fire FAQs

If you're looking for the best gas fires and you're still not sure what to go for, find out more information about some popular options below!

What are Flueless Gas Fires?

Flueless gas fires are 100% energy efficient with generally low running costs – 5p to 10p per hour. Most models are either wall hung or are as part of a traditional suite with surround hearth etc. The gas burner is designed to have very low emissions and this combined with the ODS safety device and the air vent in the room means the fires are very safe and reliable. These fires are manufactured by CVO are unique as they don’t have glass on the front or filters.

What are Balanced Flue Gas Fires?

These have an efficiency of around 85% and use a special flue liner which has two pipes. The first brings air in from outside, and the other takes away the emissions. Generally these fires are expensive to install due to the construction of the burner. All balanced flue gas fires are glass fronted with no air vent is required in the room, but a flue pipe is required to be put through the wall. The running cost depends on the Kw rating of the fire chosen and care needs to be taken not to choose a high power appliance as the efficiency will mean too much heat is generated. Balanced flue fires have a higher purchase price and can have a high cost of installation [building work and the flue pipes].

What are Open Flame Gas Fires?

Open flame gas fires have an efficiency of around 50% and use an existing chimney, pre cast flue or a flue liner. These gas fires are open flamed and no air vent is required in the room as long as the power rating is below 7kw. The beauty of open flamed gas fires is that they are visually pleasing and are able to be custom made to customer specification. With open flame fires, options are unlimited through our bespoke service. Our range includes many design styles of open flame gas fireplaces from small 2kw designs to large 20kw ribbon fires. Running costs can be between 4p/hour to 30p/hour depending on size.