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**HayZee518** · 03-11-2005, 03:38 AM

check out the circulator fan to see if it's spinning. Open the door and push the door interlock in. If it's calling for cool, then the fan should be spinning.

**LazyPup** · 03-11-2005, 10:43 AM

Ice forming in a freezer compartment is a sign of restricted air flow in the evaporator coil (cooling coils) section of the refrigerator.

As Hayzee pointed out, one of the prime causes is a defective fan motor.

The second most common cause is a problem in the defrost system. Residential refrigerator defrost systems typically have 3 components:
1.Defrost Timer
2.Defrost Heater
3.Defrost termination Switch.

The defrost timer is normally a continuous run time (although some are set up for cumulative compressor run time.)

Typically a defrost timer will allow the refrigerator to run in normal refrigeration mode for 8 hours, then it switches the refrigeration OFF and turns the defrost Heating System ON for 15 or 20 minutes. At the end of the defrost cycle the defrost system is turned off and the refrigeration On again, continually repeating that cycle.

There is a heating element attached to the refrigeration coils. That heating element is connected in series from the timer, through the heating element and a defrost termination switch.

As soon as the timer turns the Defrost System on the heater is energized to heat the coils and melt any ice that may have formed on the coils during the refrigeration cycle.

The Defrost Termination switch is a normally closed thermostat that senses the temperature of the refrigeration coil. The timer will allows the heater to be on for a full 15 minutes, but if the Defrost Termination switch senses that the coil is warm enough to insure all the ice has been melted off, the thermostat opens, turning the heating element off, and the system remains idle until the timer has run through the alloted time and switches back to refrigeration.

A leading cause of excess ice buildup is a torn or defective door gasket or a missaligned door on the refrigerator. If the gasket cannot completely seal correctly excessive moisture laden room air is drawn into the refrigerator and the ice will build up on the coils faster than the defrost system is designed to handle it.

In your post you state that if you defrost with Hot water the machine will cool correctly for two to three weeks, which would indicate the inside fan motor is probably working ok, although it may be getting obstructed when the ice builds up.

Step One would be to test your door gasket. First physically examine the door gaskets on both the freezer and food compartment for cracks, breaks or tears. Check the lower parts of the gasket to see if there are any food spills caught in the vinyl folds that may be sticking the gasket together and not allowing it to flex properly. You can clean the folds of the gasket with "Windex" type window cleaner and an old toothbrush, but be careful not to force the folds apart as they could tear. If you find a stuck part, soak it good with the window cleaner and allow it to soak a while until it can be opened easily.

To test a door gasket place a piece of paper (a dollar bill works excellant) in the door frame and close the door, the try to slide the paper up and down. If it moves very easy the gasket is not sealing properly. Move the paper to another location and repeat the test until you have gone completely around the door. If you find that the gasket appears to be in good shape but it is not sealing properly the problem may be in door alignment. This is very common on food compartment doors that have a heavy load of food on the shelves or in households where children are prone to hang on the door while peeking in the fridge.

The Door hinges have a plastic cover that will snap off revealing two screws. One is in a hole and the second one in a slot. You can slightly loosen the screws, and realign the door. The slotted screw will allow the hinge to move until you get it all aligned correctly, then tighten the screws and replace the cover.

The defrost timer is a small black box about 1.5 x 2 x 6 inches with a plug on one end where the wiring harness connects to it. On the front of the box there is a hole where a shaft from the timer protrudes through. The end of the shaft has a slot so it can be manually advanced with a coin by twisting in a clockwise direction.

The defrost timer is commonly mounted on the lower left side of the fridge at the bottom behind the kick plate, or inside the refrigerator section cabinet near where the Main Thermostat, off switch and light are. You may see a hole in the cabinet liner about 1/2" in diameter to access the timer shaft or some have a plastic button cover about an inch in diamaeter with a coin slot in the face of the button like a large screw head.

Once you locate the timer, listen to make sure the compressor motor is running. Insert a coin in the timer slot and advance the timer shaft in a clockwise direction until you hear (and possible feel) a slight click in the timer. When you hear it click, the motor should stop. Close the refrigerator door and wait about 25 minutes then chech to see if the refrigerator compressor motor started again. If it didnt restart within 25 minutes insert the coin and turn the timer. The timer should have advanced to the end of the defrost cycle and you should hear the click in the timer almost immediately when you try to turn it.
Internally defrost timers have a very small electrical clock motor that has an output gear to turn a series of geared cams. Often when they get old the cams are worn and stick. The tiny motor doesnt have enough torque to overcome the additional friction and the timer will stick right at the point where it should flip the switches. If the timer is not advancing or if it is advancing but no longer able to advance past the switching point the solution is to replace the timer.

If the door gasket, inside fan motor and defrost timer are okay, the problem will most likely be either a burned out defrost heater or a defective defrost termination switch.

To gain access to the defrost heater and termination switch you have to remove the cover over the refrigeration coils, then you can unplug the refrigerator and test for continuity through the heater and termination switch. Although servicing the heater and termination switch is not difficult, i would not recommend servicing it to any but advanced DIY'er as it is very easy to damage the refrigeration coils while servicing the heater or termination switch.

**alanthai** · 03-11-2005, 11:55 AM

Thanks for all your inputs.
The inside fan motor is still working fine.
I'll check it over this weekend and get back with you soon.

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