Water heater power cable has changed color
Based on this article:
https://en.wikipedia.org/wiki/Hard_water
and other articles discussing &quot;hard water mineral deposits&quot; I would verify that there are no symptoms of excess heat, bad insulation, or bad connections in the wire then I would consider whether the stain is &quot;brown scale&quot; (mineral deposit) caused by the evaporation and condensation of moisture in the surroundings.