I read all the literature and looked at the Harman videos and if is obvious they haven't completely updated them for the new 52i. I cleaned everything in the firebox and then removed the ash pan so I could access the combustion fan shonw in the video on the on the lower right side. I saw the lever to flip up the cover but lo and behold, no fan behind it but rather it holds a long metal covering that runs across the bottom of the back wall of the stove. I guess I want to know do I remove it to clean/vacuum whatever is behind it.