Inspected this water heater today. Everything seemed fine except for the discoloration around the burner access panel. I turned the heat up to get the heater going, no problem. No rust, great flame. Let it burn for about 2 minutes and turned the temperature back down to previous setting.
As I put the access panel back on, the edge of the opening was extremely hot. All around the tank at burner level I took a digital thermometer reading. normal, around 104. At the door opening, it went up to 212 and thus the discoloring.
Flame looked normal as did everything else. Any thoughts on the cause?