Instruction of removing FRZ sensor on BM21/25 series
Instruction Notice
Place the sensor in middle of the 
clips.
Install the FRZ sensor according to the above steps.
1
1.Remove the FRZ 
airpassage cover;
2
2.Remove the rear gasket of FRZ 
airpassage cover,then you can see 
the FRZ sensor;
3
3.Take off the sensor from the clip;
4.FRZ sensor wire