I have been running my Harman Advance in manual mode lately during the night because my igniter is not working. I am also running it in Room Temp mode. When I get up in the morning, I put the Room/Stove Temp knob in the OFF position. I know that the flame should eventually burn out and the combustion fan will shut down after a while. Lately this has not been happening all the time. The flame continues apparently because the feed is still going on. Sometimes the stove shuts down and other times it still keeps going until it runs out of fuel. What could cause the stove to not shut down after placing the Room/Stove Temp knob to OFF? I am hoping my control board is not going bad as well. Thanks for any scoop....