Displayed temperature on the ETR is offset from the actual temperature reading of the controller.
Factory calibration is offset from actual temperature.
Temperature Display Adjustments
Temperature display may be adjusted by adjusting the ZERO or OFFSET Potentiometer (P2) as shown on the diagram. Adjust P2 until the LCD Display reading, matches your controllers temperature reading if necessary.
Note that all LCD Displays, are factory calibrated using an NIST Certified Glass Thermometer.