Maplesaint,
This was my first year with a Leader 2x8 oil arch. The back of my arch is probably 4” from the wall. You can touch the back of the arch when boiling. The stack temp is to be in the 650-750 degree range. I stood 2 pieces of Leader arch board between the stack and the wall and the wall was cool behind the arch board and just barely warm above it. You can see the white arch board behind the evaporator.
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