It has been a while since some of the veteran CS owners have talked about the need for wood to burn to ash.
1st off, does your product not have a smoke flavor. Most times the product has warmed up enough that it's not gonna take on more smoke, but only lay it on the surface.
2nd, if you bend your element up to touch the bottom of the wood box MAKE sure it still has good contact with the wood box...think about a cook stove and a skillet, you need contact on all areas....so make sure your not lifting the front of the wood box up in the air.
3rd, the placement of the wood in the box WILL have an effect on the burning to ashes. Try to use the hot areas of the wood box for placement of wood, you can probably look at the bottom of the wood box for discolorment,yeah that will be the hot area.
4th, make sure you are putting the cut edge of the wood in contact with the bottom of the box...it will light faster then the split edge of the wood, experience has taught me this.
5th, sometimes in the middle of the hot summer, wood will take on some humidity from the air.
I'm sure I've forgotten something,oh!, what was your question???LOL!