Lennox MPA009S4S Service Manual page 116

Error Code:
F1, F2, F3, F4 , F5 and F6
Description: Indoor unit #1, #2, #3, #4 , #5 or #6 coil outlet temp. sensor error
General Note: If the sampling voltage is not 5V, the LED will display the failure.
Check the connections between tempera-
ture sensor and PCB. Are the connec-
tions good?
Yes
Check the resistance value of the sensor
via Appendix 1 and Appendix 2.
No
Is it normal?
No
Replace the sensor.
No
Correct the connections
Replace indoor or out-
Yes
door PCB.
116