Shorted Water Heater Element

Status
Not open for further replies.

Little Bill

Moderator
Staff member
Location
Tennessee NEC:2017
Occupation
Semi-Retired Electrician
I've heard of a heating element shorting to the tank, and that usually just results in a high Utility bill. But if it is shorted enough, and the EGC is intact, shouldn't it trip the breaker? I'm speaking of an element that has sediment build-up that bridges the gap from it to the tank.

Is it possible, even with the EGC connected, and the thermostat not calling for heat, for the element to heat the water to an excessive temperature and not trip the breaker? I do know that the elements have 240V, with one leg remaining on, and the other controlled by the Stat.
 
I've heard of a heating element shorting to the tank, and that usually just results in a high Utility bill. But if it is shorted enough, and the EGC is intact, shouldn't it trip the breaker? I'm speaking of an element that has sediment build-up that bridges the gap from it to the tank.

Is it possible, even with the EGC connected, and the thermostat not calling for heat, for the element to heat the water to an excessive temperature and not trip the breaker? I do know that the elements have 240V, with one leg remaining on, and the other controlled by the Stat.
Depends on how much of the element is left intact direct to ground. You would have 120 volt applied to the remaining part of the element. So, conceivable. The sediment buildup would be more resistive to current flow, so no breaker trip.
Most all I've replaced, the element is open. There may be some current flow through the water and sediment, but not enough to heat the water. IDR breakers tripping, just not enough hot water.
 
Sometimes the tank keeps heating enough to trip the thermal high limit, which disconnects both lines, unless water use is pretty constant, or current flow is too low.
 
Status
Not open for further replies.
Top