General Assist Technical Reference

Changing the Temperature Sensor to the Wall Controller

Indoor unit Function 42 and Function 48 configuration
Use these settings to select whether room temperature control is based on the indoor unit return-air sensor or the wall controller sensor.
The temperature sensing location can be changed from the indoor unit return-air sensor to the wall controller by adjusting Function 42 and Function 48 in the indoor unit function settings.

Function setting combinations

Function 42Function 48Control SensorDisplayed Temperature
0101Wall controllerWall controller
0000Return airWall controller

Wall controller sensing

When Function 42 = 01 and Function 48 = 01:
  • The system senses room temperature from the wall controller.
  • The wall controller temperature is used as the system control point.
  • The displayed temperature matches the temperature being used to control operation.

Return-air sensing

When Function 42 = 00 and Function 48 = 00:
  • The system senses and controls temperature from the indoor unit return-air sensor.
  • The wall controller continues to display the temperature measured at the controller.
  • The displayed temperature may differ from the temperature governing system operation.
Recommended setting: To use the wall controller sensor for both temperature display and system control, set Function 42 = 01 and Function 48 = 01.
Important: Function availability and programming steps can vary by indoor unit and controller model. Confirm the applicable installation or service manual before changing function settings.
After changing the function settings, confirm the controller display and system response. Allow sufficient time for the selected sensor reading to stabilise before assessing operation.