29/01/2026
Samsung E121,E122,E123,E151,E152,E422 Error Codes.
Checking indoor thermistors via wall controller
MWR-WE10 & MWR-WE13 Controllers
Checking the indoor thermistors via the wall controller service menu is a fast and easy way to determine the cause to a range of various error codes.
The below example, a ducted system was displaying an E422 error code (electronic expansion valve faulty). E422 is displayed after a system has run for 3-5 minutes and no temperature change has occurred across the evaporator coil.
The system assumes no temperature change has occurred due to a fault with the expansions valve. By checking the evaporator sensors via the wall controller, it was quickly identified to be a faulty evaporator inlet temperature sensor causing the error.
Depending on the controller model, you will need to either hold
Set and Escape (MWR-WE10)
Or
Set and Delete (MEW-WE13).
Regardless of controller model, you always hold set and the button to the bottom left of set.
Once in the service menu, 1 will display on the screen.
Press the up arrow until you get to menu 3.
Press the right arrow to enter the menu, sub menu 1 will display.
Use the right and left arrows to enter and exit the sub menus.
The value shown on the screen is the current temperature of that sensor.
Sub menu 1 is the return air sensor.
Sub menu 2 is the evaporator inlet sensor.
Sub menu 3 is the evaporator outlet sensor.
*Pressing Escape will exit the service menu*
