Near the end of last summer, I had a power outtage. After the outage my swamp cooler thermostat would show the temp of 22 degrees, which I assume was the lowest temp the thermostat can read. The damage was probably from a power surge.
Now the thermostat seems to correctly read the temp, but I wanted to replace it anyways. So I pulled out the wiring and found wire nut that holds the main power wires together has burned up. It looks like it shorted out, for lack of a better explaination. Thankfully the wiring is all contained in a metal box becasue the inside of the box, near where the wire nut was placed, looks like was burned.
It’s very strange, this has to have happned since I moved in becasue I replaced the thermostat. Everything still works fine. What would cause a wire nut to burn up?