How on Earth do I turn my furnace on?

[MarnelKelis]

I just started playing minetest this week and I found out that I could use a furnace to make some items. But I still have no idea how to turn it on!

I tried putting coal and wood in the two little boxes that appear when you right click on the furnace but nothing happens. It still says "fuel: 0%"

Can someone please tell me how to turn the furnace on? Thank you in advance!

[TenPlus1]

What you want to cook (ores, sand etc.) go in the top slot, the fuel you use to cook it with (coal, wood) goes in the bottom slot and the cooked item will eventually appear in the right hand slot.

[Festus1965]

Yes, as long there is no item inside to burn, melt, transform - the furnace tells by pointing at like
Item empty, fuel 0%
but as soon other upper left hole is filled with here iron ore ... it works
yes, that is not really logic, ... as soon the fuel is filled, it should also tell that so ...
but on the other way ... not fuel cant be put in there also