Gas Fires FAQs

What type of chimney or flue do I have?

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Conventional Chimney – A class 1 chimney is commonplace in houses built before 1960 and is easily recognisable by a brick chimney stack or flue rising above the roof slope. A class 1 chimney has an internal diameter of 7” (180mm) or greater. Previously the fireplace would have been used as a real solid fuel fire, especially in the case of older Victorian properties, and this is sometimes identifiable by a concrete chair brick at the back of the fire opening. Due to the age particular attention is required to ensure the existing chimney is structurally sound before any fireplace installation procedure. Class 1 chimneys tend to have a good depth and therefore generally accommodate all our range of full depth fires gas fires. However, it is worth seeking professional advice.

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Pre-Fabricated Flues – Class 1 (7″) and Class 2 (5″) – A pre-fabricated flue is generally found in older houses where the existing chimney has been lined due to the existing chimney no longer being of sound integrity, or a newer house with a purpose built steel flue built-in. They can be identified by a steel metal interlocking flue pipe (single or twin wall flue) connected to a flue box at the fireplace opening and a steel gas terminal on your roof. A flue pipe with a minimum internal diameter of 7” (180mm) or more is recognised as a class 1 flue whereas a flue pipe generally around 5” (127mm) internal diameter is recognised as a class 2 flue. Generally speaking the flue box of a pre-fabricated class 1 and class 2 flue have a pretty standard opening width 375-437mm and height 500-565mm however, the depth can vary between 196 – 330mm so be sure to check this against the fire.

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Pre-Cast Flue – Many modern houses built after 1960 do not have a class 1 brick chimney but are fitted with a pre-cast chimney system identifiable by a ridge vent or gas terminal through the roof slope. A pre-cast flue is built from gas flue blocks which are built into and bonded with the inner leaf block work of an external wall, is allows the fires to be installed within a partition or party wall or external wall. Due to the nature and type of construction pre-cast chimneys tend to be shallow in depth.

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No Chimney or Fluev – If you can’t see a chimney or flue terminating through your roof and no chimney breast in your living room then it is very likely your home doesn’t have the provisions for a conventionally flued gas fire. But this does not mean you can’t have a beautiful gas fire and fireplace. As long as your home has the provision to supply natural gas to the point of installation Superior Fires has a range of options to offer.


How do flueless gas fires work?

Flueless fires incorporate the latest in gas fire technology and do not need a chimney or flue to operate. Instead, the combustion gases pass through a catalytic converter system, positioned at the top of the appliance, which converts carbon monoxide into harmless carbon dioxide and water vapour, levels of which are so low they are typically present in fresh air. In fact, the catalytic converter works so effectively that it can actually help to clean the air by neutralising airborne particles and odours, therefore helping to reduce household allergies.

How long does the catalytic converter last?
Independent tests commissioned to establish the life expectancy of the catalytic converter have proved that even after 16,957 hours (approximately equivalent to 27 years and eight months of normal use)* the catalytic converter is as effective as when it is new.

Are they safe?
For complete safety and peace of mind all of our fires incorporate an Oxygen Depletion Sensor (ODS), which detect when the oxygen levels in the room fall below a specified level and cause the pilot flame to lift away from the sensing probe. This activates the Flame Failure Device (FFD), which cuts off the gas supply to the fire and renders the appliance safe. For additional safety, all of our flueless fires are fitted with a catalytic converter system to ensure excellent levels of air quality.

What ventilation is required?
Most heating appliances need ventilation to maintain the correct level of oxygen in the room. All of our flueless appliances installed in the UK require only 100cm² of additional purpose provided ventilation.* *For installation in the Republic of Ireland, two fixed openings are required with a minimum effective opening each of 60cm². Both ventilators should be fitted on the same wall, one at high level and one low level with a minimum vertical separation of 160cm.

What about condensation?
All of our flueless fires are designed to supplement central heating and should be used as a secondary heat source only. Therefore, the background ambient temperature of the room will prevent any moisture from condensing on colder surfaces such as single glazed windows.

Eco friendly – reducing the Greenhouse Effect
We all have our part to play in making our homes more environmentally friendly and flueless technology has been awarded five stars for eco value for money, by leading eco-consultant Donnachadh McCarthy. Article from the Sunday Times, 2006. If the 15 million flued gas fires in the UK were replaced by flueless fires, we would save 40,260,000,000 kW of gas every year which would in turn reduce carbon dioxide emissions by over 7,649,400 tonnes every year.*

*Calculation is based on the assumption of 4 hours a day for 5 months of the year. A flueless gas fire converts 100% of the gas to heat unlike open coal effect fires which convert as little as 10%. Typically running costs are less than 9 pence per hour on high, which is approximately a third of the running cost of a conventional gas fire. By choosing a flueless gas fire it is possible to make a real contribution towards reducing global warming and lower gas bills at the same time.

What safety features are on my gas fire?

All gas fires are fitted with an oxygen depletion sensor (ODS), and all fires have a flame failure device (FFD) for complete safety and peace of mind.

What is an oxygen depletion sensor and a flame supervision device?
An Oxygen Depletion Sensor (ODS) detects when oxygen levels in the room fall below a specified level and cause the pilot flame to lift away from the sensing probe. This activates the flame failure device (FFD), which cuts off the gas supply to the fire and renders the appliance safe.

Does my gas fire require an electrical supply?

Manual – Rotary Control
All our manual control gas fires feature a piezo spark ignition therefore do not require a battery or mains power supply to operate.This is benefit as you only need a Gas Safe registered engineer to install your fire and not a qualified electrician in addition.

Manual – Fingerslide
Our Fingerslide control gas fires do not require a battery or mains power supply to operate however, do require a battery (supplied) for ignition. This is located below the burner.

Remote Control
Our Remote control fires do not require a mains supply but do require a battery (supplied) for ignition. The remote control also requires batteries.

Do I need an air vent with my gas fire?

Choosing the correct air vent for your flueless gas fire is critical if you want to enjoy the full benefits of a flueless gas fire – energy efficiency and heat.

The vent is there to add fresh air to the room – not to take air out.

  • What do you mean by 100cm² ventilation? The 100cm² air vent specified in our Installation & User Manual state a “minimum amount of free air” – this is not the size of the vent (a common misconception) but is the volume of air which passes through the vent.
  • What happens if I do not have the right size air vent? If a smaller vent is fitted the fire installation will not be signed off by a Gas Safe registered engineer. In additiion it will cause the fire to be unreliable and shutdown. The same will happen if the vent is blocked.
  • What is the pupose of an air vent? The purpose is to provide fresh air ventilation to replenish the air used by the flueless gas fire. It is not to take air out.
  • Who can install my air vent?  An air vent is fitted by the same Gas Safe engineer who is fitting your fire. This is because they must be fitted in accordance with the manufacturers installation instructions otherwise this could affect your

How do I calculate the running cost of my gas fire?

The running costs of a gas fire can be calculated quite simply using the following calculation: Running Cost = Energy Input (gross) x Your Gas Bill Tariff.Example for a Blenheim High Efficiency Gas Fire: Energy Input (gross) 5.0kW x Gas Bill Tariff (gross) 4.00p/kWh = Running Cost 20.0p per hour.

Your Gas Bill Tariff figure can be taken from a recent gas bill. Alternatively contact your gas provider for this information.

This price is provided by uSwitch on the 17th July 2015 and is based upon a customer living in BH23 2BT, paying monthly by direct debit on a dual fuel tariff.