Below are some questions asked by customers. We will add to these as they occur. Please don’t hesitate to phone or email us if your question isn’t addressed here.
1. How heavy is the heater?
The core comes packed on a pallet and weighs about 1.6 tonnes. A fully constructed and faced heater can weigh 2.5 – 3 tonnes depending upon the specific details.
2. Can it sit on an existing slab?
That would require confirmation from a structural engineer as slabs vary. The distributed load from a constructed heater is in the order of 2 tonnes per square metre.
3. In your base slab photo (1) there is a piece of flue to the left. Is this just a guide for the start of the flu or does it have another application ? The written instructions don’t appear to mention this.
With our heater we carried the flue down to below floor with a cleanout at the bottom (still unused after six years) This required modification of the transfer box. The piece of flue visible is the top of the section from the sub-floor.
4. In photo (9) the transfer box is seated over the piece of flue mentioned above. You have obviously cut a hole in the top of the box to carry the flue through and up to the ceiling. Is this required? In my application I have the transfer box the other way with your top as our bottom and I plan to cut the hole through the fibre material to insert the flue. Is there a reason which prohibits doing it this way? This affords me a solid steel floor to clean it out easily later.
How you describe is how it should be (see above).
5. Is a clean out door required on the non transfer box side and if so does this also penetrate the outer wall of the smoke channel?
A cleanout door is positioned at the bottom of the side channel (let’s not hear anything about smoke; there shouldn’t be any) to enable cleanout of the connection channel that runs beneath the firebox and behind the ash drop to connect to the flue. Only small amounts of fly ash collect here. I first cleaned some out after six years.
6. Do I cement in the optional smoke channel plug or does it just sit there unsealed?
This can be just pushed in, but cement it if you wish. It is redundant if not used.
7. Is it okay to affix the temporary brackets on the main door to the core?
Yes. See page 40 of the Installation Guide.
8. Does the flue require a damper fitted on the outside at the top or is the damper in the transfer box sufficient?
The damper in the transfer box is sufficient. For safety reasons it doesn’t fully seal the flue channel and is left fully open during combustion, then closed, along with the air intake, when the fire has died down, to reduce air flow and heat loss to the flue.
9. Does the inner flue need to be stainless steel and does it require two outer flues or is this not required when the inner flue is encased inside a brick chimney?
Stainless steel is recommended for durability. If the flue is concealed within a brick chimney then outer flue layers are only required above where the brickwork ceases (above the roof in our case). Depending on your arrangements some of the residual heat can still be tapped off from the flue while it is in the internal space, either by a basket surround to the flue or by vents built into a chimney.
10. Do I need an ash drop?
If you have enough space under the floor then an ash drop can be formed there with a suitable container. A hole is formed through the base slab. If you are building directly onto a floor slab then an ash removal can be formed in the space under the firebox. A custom made pan might be used to remove the ash. Alternatively ash can be removed by lifting the fire grid and shovelling it out. There is minimal ash production so this is only required every few weeks.