Frequently Asked Questions and Answers about Fireplaces

We get asked this a lot!

  • First of all – BOTH ranges are great products within their respective price brackets!
  • Charnwood carry a 10 year (limited) guarantee and so do the Invincible Cast Iron stoves.
  • Both ranges are certified to meet ‘CE’ standards which means they qualify to be sold in Europe. Both do basically the same job of heating your home.
  • Both have been sold in South Africa for over 15 years.
  • Charnwood is manufactured entirely in the UK using components and raw materials manufactured in the UK (except the glass which is Schott Robax from Germany and raw ‘vermiculite’ which is mined in South Africa). Invincible is a robust product manufactured in China (also with Robax glass).
  • The nature of a closed combustion system means that the better the air-seal on the unit the better control you have on your fire and the more efficiently it will operate. Charnwood fireboxes are manufactured from one piece of boiler plate steel ‘wrapped around’ to create the sides. Two other plates are then welded top and bottom to create the basic ‘firebox’. The doors are cast iron. This creates a very good seal on the stove. Some Charnwood stoves have additional cast iron panels on the outer body of the stove although these do not constitute part of the firebox itself.
  • Invincible cast iron stoves are a traditional cast iron manufactured product. This means that they are made up of 6 plates, bolted together and sealed with a high heat putty/cement to make the firebox as air-tight as possible. This is the same process in the traditional ‘Dover’ stoves that you may be familiar with. This method of manufacture requires a little more maintenance over the course of time to ensure the firebox remains as air-tight as possible.
  • Boiler plate steel (Charnwood) heats up quicker – bonus. Cast Iron (Invincible and Charnwood in part) retains heat longer – bonus. Charnwood use a mixture of both materials to get the best of both worlds so to speak. Steel is less susceptible to ‘cracking’ under stress in comparison to cast iron.
  • The patented Charnwood ‘Quattro-flow’ air control system and the updated air-intake systems used on the Eco-Design ready ranges from Charnwood provide the user with a very simple mechanism to control the fire as opposed to various ‘vents’ which are used on the Invincible range. This makes it an easy ‘learning curve’ for the user. Additionally, these controls are ‘heat-resistant’ meaning you can operate them without the requirement of wearing gloves.
  • Charnwood are leading the way in manufacturing stoves to meet Eco-Design 2022 standards. These European standards will dramatically reduce the amount of ‘particulates’ that are permitted to be released into the atmosphere during the burning process of any wood-burning or multi-fuel stove made or sold in Europe. By 2022, all Charnwood stoves will meet these requirements. However, Charnwood already offer their main ranges with an ‘Eco-Design’ option.
  • South Africa sadly holds claim to having some of the worst air quality in the world according to a report by Melita Steele, senior climate and energy campaign manager for Greenpeace Africa (News 24 29th Oct 2018). Particulates cause the ‘smog’ often clearly visible over majors cities (eg Cape Town). ‘Dirty’ and inefficient heating appliances in homes are one of the contributing factors.
  • The Charnwood ‘riddle’ mechanism is second to none for burning a mix of solid fuels (e.g wood, anthracite or coal). The Invincible range has some models that incorporate a riddle mechanism but is primarily designed to be a wood-burning stove.
  • The Charnwood boiler plate steel method of construction means simpler lines for those who like a more contemporary (modern) looking fireplace.
  • Charnwood fireplaces are available in up to 8 colours (charge of R3250.00 extra).
    Invincible are available in black (with some models offering coloured side panels).

The best way to see the difference is to check the touch and feel of the units yourself which are all displayed in our showroom!

Over firing the fireplace will damage the internal components and cause the side, bottom and /or top plates to warp and/or crack and will invalidate the warranty.

Your stove will operate at the correct temperature if you can comfortably sit 1,5 to 2 meters from it. It will not be necessary to burn more than 1 average size log in a small and 2 average sized logs in a medium fireplace; and a maximum  of 4 average size logs in a large fireplace; at any given time.

Please contact us for information on any of these units. Yes, one can but they require a boiler unit.

To ensure the optimum performance of your fireplace; and for the unit to last for many years; we recommend the use of well seasoned wood. Fireplaces work the best with any dry wood, except pine & chemically treated wood. Seasoned wood can be identified when the bark comes loose by pulling it off with the hand. A suggestion may be to source well seasoned wood at the latest the end of the summer season and store it in a dry place.

A stainless steel chimney needs to be installed inside the whole length of an existing brick chimney when replacing an open fireplace with a closed combustion fireplace; when using the same chimney. In a case such as this you may find that the existing brick chimney opening and “haan” cowl at the top will not be sufficient to create a proper draw. A cyclone or turbo cowl may need to be installed on the top of the existing chimney. (see also paragraph 9.6)

All closed combustion fireplaces carry a kilowatt rating. The following formula is used for calculating what size fireplace can comfortably heat a specific volume: (L x W x H of space).

“Cubic volume of the room divided by 25  =  no of kilowatts to heat that area”    or

“Square meters of room divided by 10  =  no of kilowatts to heat the room”

It is recommended to purchase a fireplace slightly larger than calculated above. This will ensure that there will be no need to ever over fire the unit for optimal performance. The formulas above may vary and no hard and fast rule can apply for different installations. Factors such as glass windows, walls and doors, floor types, etc. can have a bearing on heat output and retained heat in a specific space. A qualified installer/ fireplace company consultant will be able to provide you with guidelines.

Ventilation is a common requirement  with the use of any form of heating. When using a closed combustion fireplace the duration of the unit working can vary from a few hours to maybe the entire day or longer. As the fireplace body radiates the heat at a constant rate, the room will become increasingly warmer. It will definitely be necessary to allow for more ventilation into the area as the case with any form of heating. Opening windows on opposite sides of the building will allow for the room to stay properly ventilated.

We supply fireplaces to all corners of South Africa from our central warehouse at Unit 4, Casadobe Park 1, London Circle Brackengate Business Park, Brackenfell Cape Town. We also have preferred dealers throughout South Africa and Namibia. Please contact us (contact details above) so that we can put you in contact with the nearest dealer to you.

The most commonly used flues are a grade 430 stainless steel.  With a standard single storey house with a roof pitch of up to 30 degrees, a flue kit consisting of a 4,2 meter flue system,  is used.

This comprises 1 x 1,2 met flue; 1 x 0,6 met flue (from the fireplace to the ceiling); 1 x 1,2 met end cap insulated flue; 1 x 1,2 met insulated flue (through the roof space up to and above the pitch of the roof) ; 1 x Cyclone cowl; 1 x ceiling plate. Additional flues may be required for the cowl to be above the highest point of the roof. Depending on the flue diameter size.

With the installation on the coast line a higher 304 grade stainless steel is used to withstand high levels of salt and moisture attacking the chromium oxide coating on the flues. These flues are 25 to 35 percent more costly than the 430 grade stainless steel. A very high grade 316 marine grade stainless steel is available on special order.

We do not recommend the use of galvanized flues, it cannot withstand the intense heat of the fire and it corrodes far sooner.

  • Baffle plate inside the fireplace not positioned correctly.
  • Poor quality anthracite. Anthracite on the market is of an inferior quality and can only be effective when used in a hot, well established wood fire. Experience has taught us to use only well seasoned wood in a slow combustion fireplace. The life span of the fire grate is also reduced significantly when using anthracite.  We do not recommend anthracite.
  • Wet wood. This happens in winter when seasoned wood can no longer be found. (Please see question 3 above)
  • A fireplace spills smoke into the room in gusting windy conditions. The flue is possibly too short (too close to the roof surface or below the pitch of the roof).  High buildings, walls, or trees too close to the chimney can contribute to this. Remember, the cowl needs a constant flow of smooth air to operate optimally. (Please see question 8 above). Occasionally, in extreme weather conditions, we have to content with the forces of nature and endure the problem. it is imperative to service the  fireplace and sweep the chimney at least every 2 years.
  • Ensure you have installed a proper cowl
  • In isolated but rare situations , an electric fan, called a “braai buddy”, has had to be installed on the top of a flue system, replacing the cowl.  This remote controlled device has proved to be a last ditch but effective solution.

The “main box”, excluding the loose components inside cast iron fireplaces, are guaranteed for 10 years.  The “main box” of the steel plate model fireplaces are guaranteed for 5 years. Both these fireplaces have a CE rating and are also marketed in Europe. Both these models perform equally effective and have been sold in South Africa for more than 14 years.

The most common problem with fireplaces is over firing. A fireplace which is cared for and not over fired will give many years of trouble free heating. Loose components, or working components, inside the fire box may need replacement from time to time. These are components such as the baffle plate, fire grate, fire bricks, ash pan, door glass, rope seal, log guard, etc (See guarantee certificate for details). The fireplace company carry a full range of these fireplace components.