That point came up in another post on another forum. The manual is definitely wishy-washy, if not wrong.
What I was trying to say is that the rear clearnces are all worked from the thermostat housing, which they want 6" from the wall, for proper...
Those clearance charts suck. The rear clearance is about the 6" between the wall and thermostat housing, not a heat issue. I wouldn't worry...