The outdoor coil sensor is critical for the defrost logic. An incorrect reading can cause the system to make wrong decisions.
Defrost too early
If the sensor indicates a lower temperature than the actual one, a defrost cycle may be triggered unnecessarily.
Defrost too late
If it indicates a higher temperature, ice may accumulate before a defrost command is issued.
Poor contact
Even a functional sensor can provide an incorrect reading if it is not properly seated at the measurement point.
Inspection
The resistance or temperature reading is compared with the technical specifications of the specific sensor.
