Frequently Asked Questions

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General questions

Most solid fuel stoves are approximately 40-50% more efficient than an open fire and allow the user to have control over the rate of burn and heat output to the room. Often a large percentage of the heat generated by central heating is lost from a room where an open fire is present (even when not in use). The installation of a stove will mean that the room is much warmer as the air flow is greatly reduced due to the installation of a register plate and the ability to close the air controls fitted on the appliance.

When a chimney was designed originally for an open fire it was typical for a fire to burn 12kW of fuel per hour and give nominally 2kW into the room. When a stove is fitted, for every 2kW it gives into the room there is less than 1kW of heat going up the chimney. Thus there is insufficient heating of the clay or stone masonry if a stove is fitted without a lining. In this situation it is typical to have tar condensation and an incorrect draught for the stove to work correctly and efficiently. A chimney lining will also prevent smoke and fumes from your fire from leaking into other rooms of the house.

Height x width x depth (in metres) divided by 14.

This is only an approximate figure and does not take into account the numerous other factors such as; the number of exterior walls, the construction of the building, how well insulated the property is, number of windows within the room or even whether there is a staircase off of the room.

We have fitted stoves in a range of properties and settings over the years and a significant number of these are properties with no chimney and no fireplace recess. In this case the solution is to have a freestanding stove connected to a flue system called twin wall flue.


A twin wall flue system is cleverly designed to keep the flue gases warm. The flue contains a thick later of insulation, normally rockwool, sandwiched between two walls of stainless steel. This insulation ensures that the stove will draw sufficiently, making it easier to light a fire and keep that fire burning. It will also keep the outside of the flue system cooler than the inside, which means that the clearance required to combustible materials is less than that of single wall flue pipe.


A twin wall flue system is made up of a number of different components that slot together and secure with locking bands. The components required vary depending on how the system will be routed; one option is to exit the twin wall flue pipe through the wall from the stove, meaning the majority of the flue pipe runs up the outside of the building. The second option is to run the flue system internally through the ceilings of each floor and through the attic space to exit at the roofline, meaning very little flue can seen from the outside.


Generally twin wall flue comes in a stainless steel finish as standard, however some customers prefer a coloured finish; black or ivory being the most requested colours. This is achieved by powder coating the flue to provide a finish that is durable and resistant to heat and corrosion.

If you have an opening that is constructed to the British Standard of  16” wide x 22” high opening, then you can have a small stove which has been designed to suit this size of opening, such as the Stockton 3. Alternatively, many people either enlarge the opening to allow for a larger appliance, or opt for an inset woodburning appliance.

Wood burning stoves have flat fuel beds because wood burns better on a flat bed of ash, with air for combustion coming from above. Multi fuel stoves are fitted with grates because coal and smokeless fuels need to burn on top of a grate, with air entering from beneath the fire and the remainder of the fuel falling through the bars. Multifuel stoves can burn wood too as they are also designed to allow you to build up a bed of ash upon which to burn logs should you wish.

A cast iron stove is slower to warm up but will radiate heat much more evenly, often providing better control.  They hold their heat for a long time after the fire has been extinguished. Originally stoves made of steel were less expensive and less sophisticated than those of cast iron. Today this is not really correct and many manufacturers are using a combination of materials to produce a high quality appliance which is both stylish and durable so the difference is really one of appearance; steel stoves tend to be of a more plain design and cast iron stoves tend to be heavier with more patterns in the design.

Airwash is the movement of air across the doors to create a barrier between the burning fire and the glass. In some stove models this air is drawn through the stove to pre-heat it to a higher temperature to give a cleaner glass when the fire is used at a medium or lower temperature.

Clean burn is a new term and really is a concept to describe the fact that some new designs of stoves are able to burn all the fuel with very low emissions. Also referred to as “secondary burn”, the most common type is where warm air is fired into the stoves firebox just above the normal height of the fire. This allows unburned products of combustion in the smoke to combust. This creates a cleaner burn as less soot is going up the chimney and into the atmosphere, meaning that the stove is more efficient as you get more heat from your fuel.

This approval allows you to use the stove with dry wood only, or approved smokeless coal, in a smoke controlled area. These restrictions are usually placed in heavily populated urban areas, normally larger towns or cities.

If you live in a smoke controlled area and wish to burn wood then yes you do, otherwise you will be breaking the law. To check if you are in a smoke controlled area click here.

DIN is the German Standards Authority which is responsible for developing new higher European standards for wood stoves. This is the highest standard in Europe and requires the best efficiency. Click here for more details.

HETAS originated as the "Heating Equipment Testing & Approval Scheme". They are the governing body of solid fuel domestic heating appliances, fuels and services and are responsible for the registration of competent installers and businesses. For more information please visit

To comply with building regulations and demonstrate that your installation has been carried out by a fully trained, competent installer.

A copy of the certificate is sent to HETAS, who will notify your Local Authority Building Control Department (LABC) of the work carried out. This saves you the time and money (sometimes up to £300) of seeking a Building Notice yourself and having an inspector from your LABC sign off the installation.


A copy of the certificate is also required to be sent to you and the installer will also retain a copy.


If you sell your home then the Solicitor acting for the buyer will require a copy. It may also required to be presented to your insurance company. Should there be a problem and HETAS do not have a record of a HETAS certificate at the property then it is likely that you may not be insured.

The new Building Regulations which were introduced in October 2010 require that a Carbon Monoxide detector be fitted in a room whenever a solid fuel appliance is installed.

If the stove has a rated heat output of over 5kW, then yes it does. This should provide 5.5cm2 of free air for every kilowatt over 5.

All woodburning stoves should be serviced and their flues swept at least once a year.  The service would include the replacement of broken or damaged, rope seals, gaskets, firebricks, glass and fire cement seals.  All moving parts should be checked in order that they are able to move freely when in operation. Corinium Stoves offers an annual service for all stoves that we install. Please click here for more details on this.

A multifuel stove can burn wood, coal, smokeless fuels and also peat.  Before purchasing a fuel it is important to check the manufacturer’s instructions which will inform you which fuels are prohibited for use within your particular appliance.

If the wood is dry it will have cracks which reach to the core of the wood often big enough to fit a coin in. The bark will usually be able to be peeled like an orange, either easy or reluctantly. If the wood is dry then the flames will burn translucent with some blue flames and leave a large quantity of embers which will burn with tiny charcoal flames whilst the stove is hot. It is possible to buy wood moisture testers to measure how dry your wood is. Morso produce one, which is stocked by Corinium Stoves and can be viewed here.

There are likely to be many suppliers local to your area, but make sure that they supply you with properly seasoned wood if you want to use the wood soon after delivery. Corinium Stoves can supply wood to anywhere within a 25 mile radius of Uley, Gloucestershire, through a partnership with Elcombe Firewood. Click here for details.

At least once a year, but up to two or three times a year, particularly if you are using your stove regularly for long periods of time. This also applies if or you are using wood that is not dry, or operating the stove at too low a temperature for extended periods, which is more likely to cause a build up of creosote in the chimney.

If you have a modern clean burning stove with airwash then the appliance may be designed to burn with clear glass: confirm this with the supplier or manufacturer. If the stove is supposed to be clean burning but the glass gets heavy deposits of tar or soot when burning wood then the problem is usually due to wet wood. The moisture from the fuel is adhering to the glass surface. Test the wood to measure its moisture content; it should be less then 20%, as anything above this means you will not be able to achieve a hot, clean fire.

Depending upon the model of the stove chosen the answer is usually yes, but there will be a dramatic reduction in appliance efficiency, unless the appliance has a damper fitted. We would recommend checking the manufacturer's instructions for details on individual appliances.

Gas Safe Register is the registration scheme for installers and maintenance engineers dealing with natural gas and LPG appliances within the UK, which replaces the previous system run by CORGI as of 1 April 2009. Corgi is still the governing body and provides support and technical guidance to both installers and home owners.

A balanced flue fire is a room sealed appliance that takes the air used for combustion from outside and deposits its products of combustion in the same way. The flues can travel both vertically and horizontally providing they comply with manufactures instructions. The flue systems are sectional and comprise of two concentric flues.

A conventional flue appliance requires a traditional or precast chimney and is not room sealed. The appliance takes its air for combustion from the room. The removal of the productions of combustion relies upon the natural draught of the flue. Sometimes these appliances need air vents within the room in order to comply with the manufacturer’s instruction or to improve the draw of the chimney.

The main difference between the two flues types are that one is room sealed taking the air from outside and the other takes the air required from the room. There are also fan flue systems.