There can be three types of deposit causing dirty stove glass. 

Dirt – Usually white smears. This is just deposits of wood ash and needs to be cleaned to improve the appearance of the fire.

Tar – An oily type of film – when minor, becoming brown treacle colour and even as black as road tar and impenetrable to light. This is as a result of the fire not being hot enough to cause complete combustion. Deposits can build up in the chimney and a chimney fire can easily result. This can be avoided by adopting two approaches; using dry fuel (<20% moisture content) and changing how the fire is operated. It is important to avoid over fuelling the fire for example letting the fire run very low and filling the firebox. Operating the stove at minimum output, with the top control closed will also cause this. A good rule of thumb is to refuel with no more than twice the weight of fuel which is left in the firebox. So if the fire is nearly out then add only a little fuel then let this burn properly before adding more fuel. This prevents the new fuel from overcooling the fire and causing it to burn in a sooty manner.

Sooting – A dusty, powder-like residue. This again is as a result of the fire burning incorrectly. The temperature of the fire is too low for the fuel to be properly burnt. Often this is accompanied by tar – but not always. If you are to use waste wood such as planks or MDF then the fuel will often produce too much flame in the early stages of operation after refuelling. This would then overwhelm the ability of the fire to burn the carbon in the flames, even if the fire is hot. There will then be sooting of the fire in the cold regions of the stove, usually the glass and around the door frame.

Cleaning the glass – There are two products available from Corinium Stoves that will clean the glass in your stove door effectively. These are the Stovax Glass Cleaning Gel and the Vitcas Stove Glass Cleaner spray (available from our showroom).

Other than these two products, you can clean the glass using a damp cloth dipped into the bed of ash at the bottom of your stove. The acid in the ash helps to clean any dirty smears.

Single wall flue pipe may also be referred to as single skin, vitreous enamel or connecting flue pipe.

Twin wall flue pipe may also be referred to as prefabricated flue pipe, factory made metal chimneys and double skin flue pipe.

Material

Single wall flue pipe is generally manufactured from steel and coated with enamel to provide a smooth internal and external finish. However it can also be manufactured using stainless steel with no enamel coating. The term “single wall” refers to the fact that there is only one layer of steel and no insulation.

Twin wall flue pipe is manufactured from stainless steel, usually of 316 grade quality. It is made up of two steel walls, which are kept separate by a layer of high grade insulation.

Finish

Single wall flue pipe is usually provided in either a matt black or gloss black finish, but can be sprayed to suit using high temperature paint.

Twin wall flue pipe is usually provided in a stainless steel finish, but can be powder coated in black or ivory to suit your preference. Powder coating is used rather than spray paint as it is more durable; twin wall flue achieves higher temperatures due to the layer of insulation.

Usage

Generally both single and twin wall flue can be used with gas, solid fuel and oil – but do check the specific product you intend to purchase.

Installation

Single wall flue pipe is designed to connect to the top or rear outlet of a stove and essentially act as the connecting piece between the stove and the main flue system. This flue system may be flexible flue liner that is installed into a masonry chimney, or it may be a twin wall flue system.

A twin wall flue system is used when a stove is fitted into a property where no masonry chimney exists. It can run internally or externally and therefore doesn’t just comprise of lengths of flue pipe that we have been discussing in this article.

You cannot use single wall flue pipe in place of twin wall flue pipe. Single wall flue pipe is not insulated and therefore loses a lot of heat. The layer of insulation in twin wall flue keeps the flue gases warmer, allowing the flue to perform correctly and efficiently, whilst also reducing the build up of condensates within the flue system.  Single wall flue pipe is also not designed to be fitted through walls, ceilings and roofs as with twin wall flue pipe. The insulation in twin wall flue allows a clearance of only 50-65mm (depending on the specific flue system) to combustible materials, whereas single wall flue needs to be three times the diameter of the pipe away from combustible materials.

An odd title to head up this blog about lining your chimney if you have a woodburning stove, but very descriptive.

Pam Ayres in her book “Surgically Enhanced” talks about an old builder who on being asked his advice on installing a woodburning stove ordered her

“to be sure to line the chimney, cause if you don’t, arter a time, runnin’ all down the inside of the brickwork, you’ll get rivers of treacle”

If only it was only treacle that was the result of a) not lining your chimney, and also b) burning wet wood.  The liquid that is produced as a result of both of these is sticky.  But that is the only characteristic it shares with treacle.  It is thick, smelly, very difficult to clean, and worst of all inflammable.

The “treacle” is actually tar, It comes out of the wood you are burning.  In a masonry chimney these deposits will stick to the sides of the chimney and after time will build up creating at a minimum a smaller draught for your woodburning stove to operate efficiently, and at worst a small river of thick, smelly gunge running down the chimney, into your fireplace, which is unsightly, smelly and a fire hazard.

Lining your chimney will minimise the likelihood of getting “rivers of treacle” down your chimney.  As will also burning dry wood.  Avoid the temptation to buy your logs of the garage forecourt.  Although they may look dry, they may well not be seasoned.  Buy your logs from a reputable log supplier, and look for logs that have been “kiln dried”.  Although they may be more expensive the amount of heat they generate will be far more than unseasoned logs.

To be certain on the moisture content of the logs you are burning, why not consider investing in a moisture meter. A moisture meter will help to confirm that your logs are indeed well seasoned.  Typically a moisture meter has two hardened steel pins which are pushed into the wood to be measured to obtain a reading of moisture content on an LCD screen.  The pins are protected by a cover when not in use.  Wood with a moisture content of 15% or less is ready to use.

Avoid those “rivers of treacle”!!!

When Santa Got Stuck Up The Chimney

When Santa got stuck up the Chimney

He began to shout

You girls and boys won’t get any toys until you get me out

My hair is black, there’s soot in my sack

Any my nose is tickly too

When Santa got stuck up the Chimney

Achoo, Achoo, Achoo!!

With today’s modern pre-fabricated chimney and flue systems, there is certainly plenty of scope for Santa getting stuck up the chimney,  With internal diameters ranging from 150mm – ideal for the typical woodburning stove, up to only 200 to 250mm for other more open appliances, Santa would not have to have eaten too many mince pies to get stuck!!

Why are modern flues so slim?  Well, they give the perfect diameter for the heating appliance to work.  They make use of modern materials and technology.  The modern pre-fabricated flue system allows the householder to have a versatile and flexible solution to created a wonderful and warming focal point within a room.

Traditional methods of building chimneys (and chimneys have been with us since Roman times!) are inefficient, require foundations and are very labour intensive.  Pre-fabricated flue systems are quick to install, the space required is minimal, allowing the building to maximise its living space.

Pre-fabricated chimney systems have been rigorously tested under European legislation gaining CE approvals along with HETAS approvals (the UK’s leading body in Solid Fuel awareness).

So what do you to say in answer to the question “how can Santa get down our chimney?”  You can of course pass it off as magic.  Just as reindeers fly through the sky, and Santa manages to deliver presents all around the world in a single night, the magic of Christmas asks us to suspend disbelief.

Or you could do what an enterprising six year old boy called Leo did.  When his family purchased a new house Leo was worried that the chimney would not be big enough to to accommodate both a large Father Christmas, and a large sack of toys.  Leo wrote a letter to the builder which said “I am worried that my mummy’s house does n’t have a big enough chimney.  I think Santa will get stuck.  Please can you help.”

The builder responded by commissioning an architect and a mathematician to design the perfect Santa-friendly chimney, on the Lower Mill Estate near Cirencester in Gloucestershire.

A crane lifted a large Father Christmas up to the roof and lowered him into the Cotswold stone chimney which goes all the way down to the sitting room.  “A perfect fit” announced Santa. “I wish they were all like this!”

Woodburning or Multifuel?

Choose a multifuel stove if you intend to burn smokeless fuels as well as wood. Multifuel stoves are fitted with a grate for the fuel to burn on with an ashpan located underneath. These grates often have a riddling mechanism that allows you to transfer the ash through to the ashpan with a push-pull handle.

Woodburning stoves do not tend to have a grate or even an ashpan – the fuel burns on the bottom of the firebox. This is because wood does not burn as hot as coal and doesn’t produce as much ash. In this instance the ash will need to be brushed/shovelled out instead.

However it is important to note that wood burns better in its own ash, so always keep a small layer of ash on the base of the firebox. Whereas if coal is sat on too much ash the fire will be hard to light and maintain, as the ash restricts the air flow to the coal for it to burn.

Steel or Cast Iron?  

There should be no difference in quality between steel and cast iron due to the high quality of the material and strict manufacturing and testing procedures.

The main difference is that steel will heat up a lot quicker than cast iron, but cast iron will retain that heat for longer. Cast iron is also easier to cast, so if you want a more detailed and decorative stove, cast iron is the material to choose.

Heat Output

An approximate calculation to find out the heat output required for your room is as follows;

Height x Width x Depth (metres) / 14 = kW output

Remember though that this calculation does not take into account how well insulated your house is, the number of external walls, windows and doors and whether you have stairs in the same room and would like to heat some of the first floor. Consider these factors and get advice from a HETAS registered engineer if you can – you may be limited by the size of your fireplace.

DEFRA Approval

DEFRA is the UK Government Department of the Environment, Food and Rural Affairs and regulates smoke emissions under the Clean Air Act 1993. If you live in a smoke control area the stove you choose must be DEFRA approved. To find out if you live in a smoke control area visit: http://smokecontrol.defra.gov.uk/locations.php

Cleanburn

Cleanburn refers to the burning of wood only. If a stove has cleanburn, this means it will burn off excess hydrocarbons in the smoke by feeding extra air into the stove. This is also referred to as secondary combustion. These excess hydrocarbons would normally be drawn up the flue and be released into the atmosphere. Therefore cleanburn results in increased heating efficiency and fewer harmful emissions into the atmosphere.

Airwash

All good quality stoves come with an airwash system. Air is flushed against the inside of the glass window, which helps reduce soot and tar deposits on the glass. However, you will still need to clean the glass from time to time. If the stove glass blackens badly and regularly it could be due to burning damp or wet wood.

Design

Some stoves come with a huge range of design options, which are generally an aesthetic choice to make. Here are some examples:

• Coloured enamel stoves such as ivory, red, green and blue.
• Canopies to sit on top of the stove.
• Decorative glass doors.
• Some freestanding contemporary stoves can come on a plinth or sit on an integrated log store, instead of the traditional four legs.

Need more advice? Contact us on 01285 659887 or via sales@corinium-stoves.co.uk.

First of all, you need to check whether your property will restrict you in terms of the fuel you can use.

Existing Chimney/Flue

• If you have a conventional brick chimney, you can choose between a wood or gas stove to sit in your fireplace opening – the difference in the installation will be the type of flue liner and terminating cowl.
• A pre-fabricated flue, which is an interlocking metal flue system, is identifiable by a metal flue and terminal on the roof and a metal flue box behind the fire. This type of flue is only suitable for gas appliances. The property will tend to have a flat wall rather than a fireplace opening, and therefore will be more suitable for a shallow, inset type gas appliance.
• New houses with no chimney may have been built with a pre-cast flue, identifiable by a ridge vent or metal terminal on the roof. This type of flue is built from concrete or clay blocks in a cavity wall. This type of flue is only suitable for gas appliances.  Again the property will tend to have a flat wall and will be more suitable for a shallow, inset type gas appliance.

No Chimney

• It is possible to have a wood or gas appliance where no chimney exists.
• Wood appliance – can be installed with a twin wall flue system, which can run through the inside of the property to exit at the roof or can exit the stove through the wall and run up the exterior of the property.
• Gas appliance – can be installed with a balanced flue, which is a horizontal pipe that vents directly outside, therefore the appliance has to be installed on an outside wall. Not all gas appliances are suitable for balanced flue installations.

Gas Supply

• If you do not have an existing natural gas supply, you can fit a number of gas appliances using LPG (liquid propane gas). Again the appliance must be installed on an outside wall, as you will require gas bottles to be fitted on the outside of the property.
• If you want to fit a woodburning appliance instead, an existing gas supply can be safely capped off by a Gas Safe registered engineer.

If you are lucky enough to have the option of choosing between wood and gas, here are some points to consider, which may help you in your decision.

Other Points to Consider

• Gas appliances are more restrictive in terms of heat output, so if you have a particularly large, open plan space to heat or want to rely on it as your main source of heat, gas may not be for you.
• Gas appliances require less attention as you do not have to keep re-fuelling the fire every few hours as with a wood appliance. Many gas appliances are also available with a remote control for ease of use.
• Although the flame effects on gas appliances are generally very realistic, for some there is nothing like the look and feel of a real log fire.
• A woodburning appliance is more environmentally friendly than gas.
• Both types of appliance will require ongoing maintenance in terms of replacement parts and annual servicing.
• The cost of using gas versus purchasing logs.

If you have a standard masonry chimney and wish to install a woodburning or multifuel stove, it is highly advisable to fit a stainless steel flexible flue liner with the stove.

Corinium Flue Systems recommends fitting a flue liner for the following reasons;

1. Masonry chimneys, particularly in older properties, are likely to have cracks. Without a liner, any fumes from the stove and creosote formed will leak through cracks in the masonry, possibly exiting in other rooms in your house or in your neighbours’.
2. Creosote is a tar like substance that is formed when fumes emitted from the stove cool down as they rise. When these gaseous fumes cool down, any substances contained within the fumes condense and are deposited on the inside of the flue or chimney. A flue liner has a smooth inner skin with less surface area for creosote to be deposited onto, whereas in a masonry chimney it is likely to build up in cracks or crevices. Creosote is highly flammable and is often the cause of chimney fires.
3. A flue liner is much narrower than a chimney and is the same diameter from top to bottom. This continuous, consistent pathway will allow the flue gases to exit the chimney much quicker, with less chance of deposits. A flue liner’s narrow, consistent diameter also means that it will warm up much quicker than a chimney. This results in an improved draw, making it easier to get a fire burning without lots of smoke back into the stove. A flue liner will also retain the heat for longer than a chimney, which means it will be easier to start a new fire the morning after the night before.
4. A flue liner is generally easier to sweep. Creosote deposits formed will be harder to remove from a large chimney, especially build ups in cracks or crevices.

A question frequently asked is whether the flue should be insulated – this is done by backfilling the chimney around the flue liner. This is not necessary, but can be beneficial if you have a particularly cold chimney i.e. external, very exposed and very large. Normally the warming of the air in the chimney surrounding the liner during burning is sufficient for insulation.

We are also frequently asked whether a flue liner is necessary to comply with building regulations. It does not state in the building regulations that a flue liner has to be fitted with a stove. However, you must be sure that the chimney is in good working condition and has been sufficiently maintained. The majority of installers and retailers will recommend fitting a flue liner; particularly in older properties, as it is safer and more efficient.

We do not advise asking your installer not to fit a flue liner purely on the basis of cost. Once you have made the one-off investment, your stove and flue liner, if properly maintained, will last for years. Most stove and flue manufacturers offer a warranty on their products – for example, we offer a ten-year warranty on our flue liner, subject to conditions of use.

Is there anything else you would like to know about flue? What article topic would you like us to write about next? Email us at sales@corinium-stoves.co.uk with the subject “Stove Man blog query/suggestion”.

If you wish to install a woodburning or multifuel stove in your property, but don’t have a chimney, there is a solution.

In this instance you will require a twin wall flue system – also called a pre-fabricated flue system. This kind of system can be routed in two ways; straight through the inside of the property to exit at the roof, or through the wall after exiting the appliance and fitted to the external wall. The pipe exiting the appliance should be vitreous enamel flue pipe, ideally at least 600mm in length. The vitreous enamel flue pipe is then connected to the twin wall pipe using a specially designed adaptor. Individual sections of twin wall pipe are connected together using locking bands and are fitted to internal and external walls using wall support brackets.

This kind of flue system can be very complex and is subject to a number of building regulations that must be complied with. For example, did you know that a twin wall flue system must be a minimum of four and a half metres from top to bottom, with a maximum of two offsets (flue gases move better through straighter systems).

I, therefore highly recommend using an experienced HETAS registered installer to design and fit your twin wall flue system.

Gas Safety Week 12-18 September 2011

 The first ever Gas Safety Week has been launched by Gas Safe Register to raise awareness of gas safety in the home.

What is Gas Safe Register?

Gas Safe Register is the official list of gas engineers who are registered to work safely and legally on gas appliances. It replaced CORGI in April 2009.

Why is it important to use a Gas Safe registered engineer?

A Gas Safe registered engineer will have been through comprehensive training and will have been certified to be able to install, service or fix your gas appliance safely and to comply with regulations. If you use an engineer who isn’t registered, you are at risk of having a poorly fitted or serviced appliance, which can cause gas leaks, fires, explosions and carbon monoxide poisoning.

A Gas Safe engineer will also notify Gas Safe Register of the gas work carried out. Gas Safe Register will then notify your local building control department.

How will I know if my engineer is Gas Safe registered?

There are a number of ways you can check:

• Visit www.gassaferegister.co.uk where you can find and check an engineer or business in your area.
• Call 0800 408 5500 to speak to an advisor.
• Ask to see your engineer’s Gas Safe Register ID card. The card will list the work the engineer is registered to do, the start and expiry dates of registration plus a security hologram and the engineer’s unique licence number.

If you find that your engineer is claiming to be Gas Safe registered but isn’t, and is therefore carrying out illegal gas work, you can report him or her via the website or telephone number detailed above.

Take care, be Gas Safe

• Always use a Gas Safe registered engineer.
• Have your appliance serviced annually to ensure safety and efficiency.
• Fit an audible carbon monoxide alarm.

With the autumn and winter seasons creeping ever closer, woodburning stoves will soon be up and running again; an efficient heat source for thousands of homes all over the country. With gas and oil prices on the increase, burning wood is not only cheaper but is more environmentally friendly as it is sustainable. However, for better fuel economy and more heat from your stove, it is important to burn the right wood.

Which Wood?

Many people in the stove industry often refer to the following poem as a general guideline:

“Beech wood fires are bright and clear
If the logs are kept a year.
Chestnut only good they say,
If for long ’tis laid away.
 
Birch and fir logs burn too fast,
Blaze up bright and do not last.
It is by the Irish said
Hawthorn bakes the sweetest bread.
Elm wood burns like churchyard mould,
E’en the very flames are cold.
 
Poplar gives a bitter smoke,
Fills your eyes and makes you choke.
Apple wood will scent your room,
With an incense like perfume.
Oak and maple, if dry and old,
Keep away the winter’s cold.
But ash wood wet or ash wood dry,
A King shall warm his slippers by. “
 
 Anon 

Whatever type of wood you choose to burn, it is important that it is dry and seasoned with a moisture content of under 20%. Kiln dried wood, which has a typical moisture content of 15-20%, does not need storing and can be burnt straight away. For wood that has not been dried or seasoned, it ideally needs to be stacked off the ground in such a way that air is able to circulate around the logs. Exposure to the sun and wind will evaporate moisture in the logs, as long as they are protected from rain and snow. To test the moisture content of your logs, we recommend using the Morso Moisture Meter; wood may often seem dry on the outside, but this is not necessarily the case on the inside.

Hotties Heatlogs

Why not try Hotties heatlogs, a new eco friendly product for use on a woodburning stove. They are made from compressed, 100% recycled, clean wood offcuts and sawdust, and contain just 4% moisture. This means they are easy to light, burn with a steady flame and give off a constant heat. Hotties heatlogs have a low ash residue and are a low smoke fuel, as well as being clean to handle and store. Please click here to view the product.

Signs You Are Burning Wet Wood

• Difficulty in lighting and maintaining a fire.
• Less heat from the fire – if the wood is wet the fire will use all its energy trying to dry out the wood.
• Blackening of the stove’s glass window.
• Smoky fires.
• Excessive build up of creosote, a tar-like substance, in the flue or chimney that causes blockages and restricts air flow. This is dangerous as creosote is a highly flammable material and is often the cause of chimney fires.