Steffes paints the panels of the heater with a high quality powder finish that should last the life of the product. However, discoloration of the front panel can occur under two circumstances:
Staining of the front panel caused by oxidizing of air borne particles in the home. After air borne particles are oxidized, they are expelled back into the room and may accumulate on the heater or other surfaces. Over time, these particles may build up a residue on the front of the heater directly above the air discharge area. Cleaning the outer surface of the heater with a nonabrasive household cleaner will generally remove this discoloration. Refer to maintenance and cleaning for more information.
Hot air from the brick core leaking to the front panel. If damage to the insulation package occurs, if bricks are loaded improperly, or if the galvanized front panel is installed incorrectly, air from the brick core may leak out. This air will cause the front panel to become hot and will eventually discolor the paint. This discoloration is generally seen in the upper left corner of the front panel, but can occur in other locations around the core. It is extremely important to contact a service technician and have the heater inspected.