We caused our Atwood propane hot water tank to melt some of the control wires.
Since we have an electric refrigerator, we decided that we don't need propane on all the time, so we turned the tank gas valve off.
We forgot we had the gas turned off and turned on the hot water tank propane switch to heat the water. A very small gas flame lit, and because it did not have its normal pressure, the flame did not shoot into the burner. Instead it dribbled up toward the board wires and melted several wires.
Problem was caused by not turning the tank valve completely off.
The thermal fuse is supposed to catch this problem, but it was placed a little too far from the wires. I now have several thermal fuses in a line, one plugged into the next to cover all the areas an errant flame would go.
I think that using several thermal fuses in hot water tank burner area is a good idea as one does not know where a misplace flame will go.
Atwood 93866 Thermal Cut Off Kit, (Pack of 2) : Amazon.com : Automotive (http://www.amazon.com/Atwood-93866-Thermal-Cut-Pack/dp/B0007XXTVC)
George's question on using thermal fuses for his refrigerator fan reminded me of our wire problem last year.