The main goal of every fridge is to generate frost of course, but without proper defrosting cycle refrigerator may start failing. The defrost cycle should be conducted regularly to avoid the excessive ice condensation on the evaporator coils. It may lead to the malfunctioning of all systems of your fridge and to the spoiling of your food inside. There are many causes of the defrosting cycle faults and today we want to tell you about the most common.
Remember to unplug your appliances before the repairs! Be careful!
The purpose of the main control board is a regulation of the power supply for all refrigerator parts. Defrost system receives power from the MCB. If the MCB is malfunctioning it may cause defrost system faults as well. But don’t hurry to replace the main control board, provide the diagnostics of all defrost system components first. If you determine that the defrost system is fully functioning you probably have to replace the main control board.
The defrost control panel regulates a defrost cycle frequency. If it’s faulty, the defrost cycle may not begin at all or it will be run with the wrong frequency, causing system malfunction. Before replacing the defrost controls make sure to test other parts first. The defrost heater and defrost thermostat deserve special attention. In case those are working properly the problem is likely caused by the control panel.
The main goal of the defrost thermostat is to monitor the evaporator coil temperature. Whenever the coil temperature drops below the preset, the thermostat may execute the contact closure to begin power flow into the defrost heater. Defrost heater will melt frost accumulated on the evaporator coils. In case the thermostat is faulty, the contact closure will be impossible and the defrost cycle won’t begin. Use a multimeter to diagnose the thermostat. In case the thermostat is losing its continuity on the lowest operating range temperature it has to be replaced.
The defrost heater assembly has to turn on periodically throughout the refrigerator working cycle to melt frost and ice condensations away from the evaporator coils. If the heater assembly is defective the defrost cycle will not run correctly and ice will concentrate on the evaporator coils continuously. Test heater’s continuity with a multimeter and in case the continuity is broken, replace the defrost heater assembly.
The purpose of the defrost timer is to activate the defrost heater periodically to clean the evaporator coils from the condensed frost and ice. The defrost cycle may not begin, or power won’t be sent to the defrost heater during the defrost cycle if the timer is faulty. Advance the dial into the defrost cycle gently to make sure it works fine. The heater should turn on while the compressor should turn off. If power won’t be sent to the defrost system components or the defrost cycle will be over within 30 minutes – it is most likely that the timer is malfunctioning. In this case, replace it.
The defrost sensor monitors the evaporator temperature. The sensor is equipped with a fuse that will disable the sensor in case of the sensor’s breakdown. If it fails to shut off the heater, the fuse will burn out in order to stop the defrost heater and prevent overheating. After that the defrost system will fail and refrigerator won’t defrost until the sensor replacement. Examine both the sensor and the fuse using the multimeter to check their continuity. Replace the sensor if it’s faulty or replace the fuse if it’s burned.
Attention! We highly recommend NOT to perform the repair if you have no prior practical experience in electrical repair, because it may pose danger to your health and your property. Call the experts and we’ll fix all faults in no time without any risks for you!
