Fireplaces

The different types of fire require different sized openings to the flue. Note All dimensions are for guidance only - for any product check the manufacturer's trade literature for actual figures.

Flues

Most gas fires require a suitable flue, brick or masonry chimney.

Flues must be:

The Chairbrick

This is the chair-shaped brick arrangement at the back of the fireplace (the catchment area), which sticks into the fireplace and helps create an up draught in a coal fire. This may have to be removed if there is not a large enough gap to the back of the fireplace with the gas fire in place.

Hearths

Floor-standing gas fires cannot go onto carpet or floorboards they must have a hearth. The hearth must:

Be made of solid, non-combustable material - at least 12.5mm thick and 50mm above floor level.

Have a surface that must be relatively smooth and level.

Extend at least 150mm beyond each edge of the naked flame or radiant.

Extend at least 300mm from the nearest burner - effectively the front of the fire.

For further detailed information see your gas fire installation instructions.

Ventilation Requirements

Fires or heaters that take their air for burning gas directly from the room (with open or fan-assisted flues - not balanced flues) must have adequate ventilation. For most fires, normal room ventilation is adequate.

Fires with high input/low heat output (normally decorative gas fires), however, do require a permanent ventilation opening of 100cm2. Check with manufacturer's instructions.

Concealing Pipework

The gas pipework to the fire does not have to run along a skirting or wall - it can be concealed in a number of ways:

It can feed through the side of a chimney breast.

It can be chased into the brickwork leading to the fire and then covered.

It can be installed behind a surround or plinth.

Flueless Fires & Mobile Heaters

Flueless Fires

Room air is drawn in below the fire, as it rises through the rear heat exchanger it is heated. As the heated air passes over the top of the fire the hot combustion air joins it after it has passed through the catalytic block, which removes the poisonous gases.

The catalytic blocks used in these appliances have an expected life span well in excess of ten years or normal domestic use. Concentrated life testing is continuing and no catalytic failiures have occured as they only use high quality cataytic blocks which should outlive the appliances.

Purpose provided ventilation is required with appliances of this type.

As with any gas appliance, regular servicing is essential to ensure continued safe use. It is recommended that these fires are serviced every year by a CORGI registered installer.

Mobile Heaters

All new portable cabinet heaters made to British Standards BS 5258 Parts 10, 11and BS EN449 are fitted with a special safety device that cuts off the gas supply if the room gets too stuffy. This is called an Oxygen Depletion Sensor (ODS).

Due to the restrictions in the quantity of fuel stored (7, 11 and 15kg) they are allowed to be flueless although they do also burn ‘clean’. Manufacturers recommend that they be installed in a well-ventilated room.

Balanced & Fanned Flues

If no chimney or other open flue is available, fires or heaters can still be mounted, on an outside wall (only), using a balanced or fanned flue. This very effective flue actually seals the product off from the room it is being used in - the air for ventilation comes from outside and the products of combustion cannot enter the room. For this reason, they are called room-sealed products.

Balanced Flues

A balanced flue has two channels - one to draw in air to burn with the gas, the other to get rid of the products of combustion.

Fanned Flue

Similar to a balanced flue, the flue is led from the product to a flue box, which is open to the outside air.

The products of combustion are dispersed in one of two ways:

1. Afan in the flue box draws them along the flue from the fire or heater

2. Afan in the fire or heater pushes them along the flue until they emerge into the outside air.

Terminal Guards

Where balanced or fan-assisted flues come out of the wall less than two metres above ground level (or balcony level in flats) you must fit a wire terminal guard to prevent people or animals coming into contact with hot products of combustion.

Electricity

All fanned flue fires require an electric point near to the chosen fixing point.

Ventilation

Some appliances will need ventilation and this will de determined by the manufacturer.

Chimneys & Flues

In order to function correctly (and conform to safety regulations) fires and wall heaters need to be fitted to appropriate flue. There are also extensive requirements for the installation and ventilation of fires and wall heaters.

Types of Flues

Burning gas in air creates a number of by-products - the products of combustion. Where gas is burnt in any quantity (gas fires, water heaters and so on - but not cookers) these by-products will accumulate quite quickly - which may be harmful. They must, therefore, be removed. A flue takes the products of combustion out of the room and dissipates them in the outside air.

Customers may already have or require one of the following types of open flue:

Open Flue

An open flue is simply a flue which is open to the room is serves. The products of combustion rise up it by convection

Conventional Brick Built Chimney

Combustion products rise through convection and are also drawn up by wind passing the top of the chimney. These are built in to the design of the house. and are commonly referred to as class 1 Flues.

Pre-Cast Concrete Flue

Common in newer homes, these are built into the original walls - without increasing their thickness. Commonly referred to as a class 2 Flue, these are uncommon in Jersey.

Prefabricated Flue (Twin Wall)

Usually a later addition, this is a twin - skinned flue made from stainless steel which is attached to the inside of a wall and led away either through the roof or through an outside wall.

These are sometimes boarded over to imitate a chimneybreast. - Class 2 Flue if less than 125 mm.