Frigidaire Refrigerator Repair
Frigidaire refrigerator: model #FRT16CRHW4
The Frigidaire refrigerator makes a slight, subtle whistling noise. This happens frequently, every five minutes or so, and the noise lasts a couple of seconds. This high-pitched whine seems to be coming from the back of the refrigerator.
This sounds like the noise that the refrigerator makes when the refrigerant is going through the tubing.
On newer units, manufacturers actually use smaller tubing for the condenser because it helps condense the refrigerant a little more efficiently. Because more refrigerant is being pushed through a smaller tube, the noise and high-pitched sounds are coming from the tubing.
In some Frigidaire refrigerators, the actual drier, that helps drain and keeps the refrigerant clean, might need to be adjusted. It could be what is causing the noise.
Frigidaire Refrigerator, Model FRT21IL5DB0
Noisy during the defrost cycle, makes snapping or popping sounds
This is normal operation. When the unit goes into defrost, it turns off the compressor and turns on a defrost heater (part #5303918247) behind the back wall in the freezer. It melts all the frost and ice off the cooling coil and then it drips through a little trough to the underside of the refrigerator where that water evaporates into the room air. When that frost turns to water, you get a lot of cracking similar to throwing ice cubes in a glass of water. And the hissing sound is also normal because water is dripping on a hot heating element.
If the sound is bothering you, these units have a defrost timer, so you can set the timing of the defrost cycle to when it won't bother you.