Frequently Asked Questions about Fireplaces

If you can't find the answer to your question here please telephone us on 021 979 4567.


1. How hot can I run my stove?

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 2 average size logs in a small and 3 average sized logs in a medium fireplace; and a maximum  of 5 average size logs in a large fireplace; at any given time.


2. Can I heat radiators, under floor heating, pools or domestic hot water from a fireplace?

Please contact us for information on any of these requirements.


3. Do I need to burn seasoned wood on my stove?

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 blue gum and black wattle timber that has been sourced from the veld where it has been cut down and exposed to the elements of a season of very hot dry weather.  Seasoned wood can be identified when the bark comes loose be pulling it off with the hand. A suggestion may be to source seasoned wood at the end of the summer season and store it in a dry place.


4. Does my existing chimney need a lining?

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; and when using the same chimney. In a case such as this you may find that the existing brick chimney opening 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 brick chimney. (see also paragraph 9.6)


5. What size stove do I need?

All closed combustion fireplaces carry a kilowatt rating. The following formula is used for calculating what size fireplace can comfortably heat a specific area or volume:

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

When the room(s) are fitted with a standard height ceiling of about 2,5 / 2,6 meters, you may use this formula:

“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 insure 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 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.


6. Do I need ventilation in the room that the fireplace is in?

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. Opening windows on opposite sides of the building will allow for the room to stay properly ventilated.


7. Where can I find my closest Invincible fireplace dealer?

We supply fireplaces to all corners of South Africa from our central warehouse at No 1 new street, Durbanville, Cape Town. Please contact us (contact details above) so that we can put you in contact with the nearest to you, approved dealer.


8. What type of flue (chimney pipe) should I use?

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, the cost of a standard 430 stainless steel flue kit is from about  R5000.00 inc vat (2015 prices)

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 40 to 50 percent more costly than the 430 grade stainless steel. A very high grade 316 grade stainless steel is available on special order.

We do not recommend the use of galvanized flues.


9. Why is my fireplace smoking?

9.1   Baffle plate inside the fireplace not positioned correctly.

9.2   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.

9.3   Wet wood. This happens in winter when seasoned wood can no longer be found. (Please see question 3 above)

9.4   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 be a cause. 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.

9.5   Ensure you have installed a proper cowl

9.6   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.


10. What is the guarantee on, and expected life span, of an Invincible cast iron closed combustion fireplace?

The “main box”, excluding the loose components inside the 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 10 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 will need replacement from time to time. These are components such as the baffle plate, fire grate, fire bricks, ash pan, door glass, log guard, etc. These items are not covered by the respective 10 and 5 year guarantees. The fireplace company carry a full range of these fireplace components.



the fireplace company