When we turn on the electric switch for the Atwood WH, we get a pretty strong smell from the WH, inside the TT. It smells like overheated wiring. We replaced the temperature sensors, but that did fix it. I have read that it could be the element, but I am not sure.
I would not recommend running this thing in anything other than troubleshooting mode. Burning wiring can cause a fire.
If your water heater has outside access, remove the grill and fire it up (so to speak). See if the smell is coming from that area. If so, turn the unit off and disconnect from power. Then feel around the wires to see if you can find a hot one. The reason I say to disconnect from power is just to avoid any shock from a wire that may have melted through.
In theory the unit's circuit breaker is suppose to be there to protect the wiring in case of excess current draw. To smell burning wiring is somewhat unusual as you would hope the breaker would trip before any wiring got that hot. The wiring should get warm but not hot.
A loose connection to the heating element could cause excessive heat. I would look first at the heating element wires and work my way back.
Be very careful troubleshooting this sort of problem. You don't want to burn down your rig.
Retired electronic technician (45 years in the field)
2017 Greyhawk 29W
solar & many other mods
wife (maybe I should have given her top billing)
I will heed your advice. I do not know that it is a wire; it is a similar "plastic" sort of smell. It could be something else. It seems to be coming from the back of the unit. It also smells a bit like styrofoam. It has a styrofoam cover on it.