Richmond electric ECO water heater not heating - RESOLVED

I have a Richmond 12E50-DEC 50 gallon water heater which has digital controls in which after powering off/on with the circuit breaker can be set to heat, but oly powers the upper electric element fo around 1 minute, then the digital control disables the voltage to the heater element. Lower element never gets voltage applied.

Both elements are both 11.5 ohms and appear to be good. Am attempting to remove and measure the thermocouple but using the digital diagnostic, I observe lower on at 54 F and upper at 77F, so are somewhat reasonable values for a tank that was at room temperature and then had some water come in from the well into the lower chamber.

I understand that these controls me only turn on one heater element at a time which would explain the upper element getting voltage for 30 seconds or a minute but then unclear why the control with turn off the heat without posting any kind of error code as there are no codes in the history.

Any help would be appreciated.

Called Richmond (Rheam) customer service.The representative felt this was likely a faulty digital circuit board since no error codes were being posted in the history and due to the behavior observed where the upper element was powered for about a minute after a power cycling off/on using the circuit breaker. Service person advised me that the upper heater element would normally be powered for about 20 minutes before switching power to the lower heater element.

New circuit board being sent free of charge under the 12 year parts warranty.