Water Heater Electrical Issue

[John Evans]

Two year old electric water heater. We were not getting any hot water during the inspection. I opened the upper thermostat panel, and discovered complete burn damage to the electrical wiring. Any thoughts on the cause? The home had been vacant for a short amount of time prior to the inspection.

[Michael Roberson]

Looks like either a bad connection, or plain old overheated wire. What size breaker/wire was used?

[John Evans]

30 AMP breaker with #10 conductor. The lower element thermostat was not damaged.

[Michael R. Boyett]

I'm guessing that the water supply was off to the home for some period of time, faucets were turned on during that time and the water level fell in the tank, the heating element came on and overheated due to no water in the upper part of the tank, therefore no heatsink for the element, it got too hot and burned the element and wiring up due to excessive heat, not an electrical 'short' per se.

[Larry F. Rollins]

Usually the element will burn out so quickly that no external heat will be noted. There are, however, elements that can be energized in open air without burning out.
I think It was a short of some type. I have seen long sections of #10 wire literally melt without a 30 amp breaker tripping at all. The reason that the lower section is fine is that on residential heaters no power is allowed to be sent to the bottom element until the top element turns off(top of tank is hot).

[Jeffrey R. Pope]

Originally Posted by mboyett

I'm guessing that the water supply was off to the home for some period of time, faucets were turned on during that time and the water level fell in the tank, the heating element came on and overheated due to no water in the upper part of the tank, therefore no heatsink for the element, it got too hot and burned the element and wiring up due to excessive heat, not an electrical 'short' per se.

That would be in line with my guess as well. Possibly a "winterized" home and the power to the unit was turned on, or left on.

[ROBERT W. NEWLAND, JR.]

I inspected a foreclosure yesterday and found out agent and client turned all the breakers on themselves. Water was off and tank was empty. I can only imagine the tank is fried .