- Check that the de-icing thermostat is in the correct position and connected to the condenser tube;
- Measure the temperature in the tube next to the de-icing thermostat sensor;
- If the temperature is above -4 ° C, measure the voltage on the coil (voltage must be present);
- Defrost thermostat cables disconnected, measure the continuity between them, the temperature below -4 ° C should not continue and with the temperature above 18 ° C it should continue.