I finally got the temp down to about 135*F and the TPR valve remains closed.
It remains a mystery as to why the thermostats were reading low and yielding too high a temperature.
The water pressure is about 60 PSI.
Why would a TPR valve fail in a low temp mode?
I plan on replacing the TPR and using a tubing to join the 3/4" copper tubing.
There should be a TPR open sensor thingy that cuts off the power. You waste energy and water when it fails. We just returned from a 10 day trip and luckily we had the water heater power off.