Balanced Flue

A balanced flue, sometimes more correctly referred to as a room-sealed appliance, can be a solution where a property has no masonry chimney and a freestanding flue-pipe would be inappropriate.

Balanced Flue
Balanced Flue


It uses twin pipes or ducts coming straight from the back of the cooker through the wall to the outside. One tube brings a fresh air supply into each of the burners, whilst the others discharge the products of combustion.

On oil-fired models this takes the form of two rectangular ducts, whilst the gas-fired cooker has two concentric tubes and an external protective cage covers the terminals.



Solid fuel and wood burning appliances can not utilise the balanced flue system.  Although no bends can be fitted in the flue-pipe, the overall length can be up to 1 m which is more than adequate for most domestic wall thicknesses.

Do not hesitate to contact us at gasmarkone for any help and advice concerning your choice of Rayburn, fuel type or installation concerns.  We are always here to help you make the right choices for your home.

Balanced Flue Restrictions and Regulations

Current regulations dictate where a balanced flue can terminate and there are minimum clearances required to nearby obstructions or opening windows & doors. They should not terminate within car-ports.  Our engineers carry out assessments ensuring noise or vapours don’t cause annoyance to neighbours.  At gasmarkone, our  Rayburn Guild installers will advise you of the best place for installation.

Rayburn Models

The gas 480CD and oil 680CD have high-efficiency ‘A’ rated boilers operating on the condensing principle,  extracting every last bit of heat from the flue gases. The flue-pipe design leads any condensate safely away to a convenient drain or soak-away.  The burners and flue-path are sealed from the room which removes the need for air-bricks into the kitchen.

Oven Venting

Oven venting is an important product feature, separate copper pipes vent the ovens to outside, removing cooking smells and condensation. Some models have an additional electric fan to assist in this process.