[rickst29]

If you've done manual reset on the 12v switch, the next possible failure occurs at the 12v thermostat limit switch.

12v should be going into that switch when you activate the Apron switch. (Check it). If 12v is present at the input side but NOT PRESENT on the outside of that temp limiter switch while the tank is cold, then the thermostat limit switch has gone bad. replace it.

If 12v does come out of the thermo-limit switch, then check the red wires on the module board. (Possible bad switch at the Apron.) If 12v not being fed back to the module board, replace the Apron switch.

If 12v is present from the module board on the wire to the indicator light, then the light has burned out. But if 12v is not present on that wire, then the module board has gone bad. replace the board. I attached the portion of the service manual 'troubleshooting' page 22 which is relevant to the apron indicator light NOT EVEN COMING ON.

I hope that it's a failed apron switch or thermostat limiter, the module board is more expensive.