How can I be sure that the interior chamber is cleaned out? I vacuumed it going in both holes and using a flexible brush in try to get everything lose. But there is no way to actually see inside. The problem I am having is where the warm air blows out the front vent. The air coming out the right side of the vent is warm but air coming out the left side is cool. I have been told to make sure the interior chamber is clean and I think I did that. What else could cause this problem? Can anyone tell me or have a diagram that shows what the interior chamber looks like inside and tells how the ash gets in there? The manual does not have any detailed description, instructions or drawing. It just says to make sure its clean along with everything else. Ideas? Thanks.