If your refrigerator seems to be getting louder, you can learn about the causes of refrigerator noises and alleviate the problem. Once you identify where the noise is coming from, you can proceed with any repairs or service to your fridge.
Noise Coming From the Back
If the offending noise is coming from the back of the fridge, there are three possible components that could be making the noise: the condenser fan, the defrost timer, or the compressor.
The condenser fan is located in the back of the fridge not too far from the compressor, behind a protective panel. If the noise appears to come from that area, it could be caused by an unbalanced fan resulting from dust or lint accumulation between the fan blades.
But before attempting any repairs on a fridge UNPLUG IT FROM ITS OUTLET to ensure you will not end up getting a serious shock, you don't create a short circuit, or a moving part such as a fan doesn't harm you while starting unexpectedly. If there is something in the way, there is also a chance a fan could get damaged while uncovered.
The next step is to get to the condenser fan. After removing the protective cover, give it a thorough inspection looking for damaged blade(s) or dirt buildups on the blades. Use a soft brush to clean between the fan blades, but if there doesn't appear to be any debris buildup, you may have to replace the motor as the noise will be indicating that it is faulty.
The compressor can be found on the outside of the fridge, in the bottom at the back. It's a big black unit, quite heavy, and sitting on four rubber mounts that absorb its vibrations while running. It also has copper tubings and wires running from it. If the noise is coming from the compressor, it could be from a faulty timed relay controlling the starting of the compressor or it could be from the compressor itself. Either way, you will have to replace the defective part.
This is a costly replacement if it is about the compressor itself, so make sure you're troubleshooting your refrigerator correctly to avoid unnecessary and expensive part replacements.
The defrost timer can be located in different places depending on the make and model of the fridge. It's a small plastic unit, usually white in color, and it usually has four terminals extending from it on one side. The most likely places where it can be found is behind the kickplate, behind the fridge on the back wall, or in the refrigerator's control panel. If the noise comes from inside the control, it will have to be replaced, but on a lighter note, it's not expensive to buy and you can replace it yourself.
Noise Coming From the Inside
If you have a self-defrosting fridge, the noise is most likely coming from the inside. This is because these types of refrigerators use a fan to circulate air through the fridge and freezer. The fan is situated in the freezer, but exactly where will depend on the kind of fridge you have.
If your freezer is on the left side of your fridge, the fan will be located on the back wall near the top. If your freezer is on the bottom, your fan will be on the back wall near the top of the freezer. If your freezer is on the top portion of your refrigerator, your circulating fan will be on the back wall in the middle of the freezer.
To test if the noise being made is from the circulation fan, open your freezer and push in the light switch. If the noise becomes louder, you will know it's from the fan. This fan is often protected by a plastic cover, behind which the light is often hidden from view.
If the freezer gets overfilled with frozen food, it's possible this cover may have been accidentally displaced against the fan blades causing the noise. Check by unclipping and removing the cover, and after inspecting the fan blades for damage, if all is good, replace the cover and retry. If the noise persists, the part will need to be replaced.
Noise Coming From the Bottom
The easiest repair to make is when a rattling noise is coming from the bottom of the fridge. In this case, the most likely culprit is the drain pan which sits under the fridge. This pan can start to rattle from time to time so all you need to do is secure it back in place to make the noise stop.