I can see through the window that it's almost full. I read about an error code in the manual. How does it know? It's too late at night, not willing to wake up the man of the house to empty it since he's likely deep asleep after a long week. Personally I don't want to turn it off, but its a long cold walk for me to go to the incinerator where we dump the ashes. Guess I will turn it off and stay warm in bed I have never seen the code before (ash pan never this full before) but quite curious how it would know?
I do not believe your stove will sense the ash pan is full. What happens is there will be an error for pressure or perhaps sensing enough heat if ash is blocking certain pathways or sensors. This could happen with an empty ash pan but dirty stove.