OK. I’m perplexed.
I’ve replaced both elements AND both thermostats.
Now only the upper stat has a red overtemp reset button. Both thermostats ARE adjustable and set to 120.
Both thermostats appear to be held firmly against the tank.
When I went to bed, temp at the tap was ~165. The overtemp had popped this morning.
I can only think to check the wiring w/a meter.
Anybody have any clues ?