Good morning. So, I threw the breakers off, set the m-meter at 1k, and placed one probe on screw and one probe on the inside-most layer of metal I could reach – assume that is the actual tank. No movement at either screw of either element. (Yes, meter zeroes out, and I had the covers off the probes!) Also tried grounding to each of the three copper pipes: Nothing.
I’ll agree that what I called a loud pop is actually a click that I had not been expecting right next to my head. The hissing starts a few seconds after it clicks when I turn the t-stat back down – it is coming from the upper portion of the tank.
But, if we attribute the melted t-stat to a power surge, your decription of the symptoms of a grounded element sound right on: “water getting exteremely hot and reset button popping out.”
Could the grounding be intermittant? Or at an early stage of development that does not register yet?
In the first event the tap temp went to 170 and stayed steady for several days. In the second incident, I did not check the tap temp – it was just hotter than usual. In the most recent event, it did not get all that hot and was extra-warm for only a couple of days before the reset button popped. Could it be progressing?