You can expect a refrigerator to make a certain amount of noise when it starts to cool your food. Typically, it is a very low hum that you really only notice when you are standing right next to it. However, when your refrigerator has become progressively louder, so that you may even be able to hear it running in the next room, this is not normal.
A louder refrigerator does not always necessarily need a repair, but there are a few things that you can check.
Dirty Condenser Coils
The condenser coils located on the back or bottom of your refrigerator require regular cleaning to perform their function efficiently. When they grow dirty and have to work harder to stay cool, it may cause your refrigerator to become louder in turn. If they become dirty enough, it may even cause your refrigerator to run more frequently as well. As this is a task of cleaning rather than repair, it should be your first stop when diagnosing a loud refrigerator.
A refrigerator, like any appliance, is not immune to time. Over its life cycle, the compressor will begin to wear down and it will grow louder. If this is the case, you will notice that the noise is much louder when you open your refrigerator while it is running.
If an older compressor is making the noise, it does not necessarily mean it needs immediate repair, but sometime in the near future, that compressor is going to fail and a repair technician will need to replace it before that happens.
If the fan becomes loose and starts rattling or is partially obstructed, it will create quite a bit of noise until it is fixed. Typically, it has a very distinct rattling when it is manifesting problems, making this easy to diagnose and easy to fix. It could be a case of removing the obstruction or tightening and realigning the fan rather than replacing it.
Water Inlet Valve Build-Up
If you have hard water or unfiltered water, minerals can build up inside the water inlet valve. This, in turn, will make the refrigerator loud when this water function is in use. If you only notice loud noises sometimes, like when your ice maker starts filling, then this is a likely culprit.