THIS PROCEDURE MUST BE PERFORMED BY A QUALIFIED TECHNICIAN.
THIS PROCEDURE MUST BE PERFORMED BY A QUALIFIED TECHNICIAN.
Error 1 corresponds to the lower core (Core A) and Error 2 the upper core (Core B). The errors indicate that the thermocouple temperature is out of normal operating range. Errors 1 and 2 are triggered when the sensed core temperature exceeds 200°F above the maximum core temperature (L040) or lower than -100°F. A defective thermocouple or a circuit board which is out of calibration can cause this. In addition a stuck relay causing an element to stay on, improper phasing of input power, or a strong RF environment may be other causes.
Verify that the lower core thermocouple wires are connected to the lower two terminals on the processor control board and that the upper core thermocouple wires are connected to the upper two terminals on the processor control board. Verify the polarity of the red and yellow wires to ensure proper operation of the system. 4120 systems only have one core thermocouple (Core A), connected to the lower two terminals.