Modern refrigerators have new features and are more energy efficient than older ones. The foam insulation used in new models has excellent insulating capabilities and is very energy efficient however it is not as sound absorbent as previously used fiberglass insulation.
Hard surfaces such as ceramic tile, vinyl or hard wood floors, walls and kitchen cabinets may make these operating sounds more noticeable. As a result, certain sounds may be unfamiliar on a new refrigerator at first. These sounds are normal and are usually an indication that the refrigerator is operating properly.
Listed below are descriptions of some of the most common sounds you may hear, what is causing them and some exceptions to look out for.
1. Evaporator (cooling) Coil.
The flow of refrigerant through the evaporator may create a boiling, surging or gurgling sound especially at start up and shut down of the compressor. After defrosting, a popping sound may occur as it expands and contracts with changing temperatures.
2. Evaporator (freezer) Fan.
You may hear air being forced through the cabinet by this fan.
Abnormal: A continuous, rhythmic ticking sound when running or an intermittent or constant squealing sound.
3. Defrost Heater.
During defrost cycles water dripping onto the heater may cause a sizzling or hissing sound.
Modern, high efficiency compressors operate much faster than older models. The compressor may have a high pitched hum, whine or pulsating sound.
Abnormal: Repeated clicking sounds seconds apart during start up, possibly accompanied by dimming lights. Banging or knocking during start up or more commonly, during compressor shut down. A ping or metallic snap followed by compressor inactivity.
5. Cold Control & Defrost Timer.
These parts can produce a snapping sound when turning the refrigerator on or off. The timer may also produce a sound similar to the ticking of a clock.
6. Plastic Liner.
Cracking or popping sounds due to expansion of the plastic liner as temperatures change.
7. Moistural (aka drain) Pan.
Water may be heard running into the drain pan during and just after the defrost cycle.
7b. Defrost Water Drain. (not shown)
You may hear a gurgling sound as air enters or exits the cabinet when the doors are opened or closed.
While this usually doesn't present any problems, there may be a repair kit available from the manufacturer to help quiet the sound.
8. Water Valve.
(on models equipped with an automatic icemaker or water dispenser).
When the icemaker fills or water is dispensed, a buzzing or click and running water may be heard.
9. Icemaker (on some models).
Occasionally you will hear the cracking of ice and ice cubes dropping into the ice bin.
10. Condenser Fan.
You may hear air being forced over the condenser by this fan.
Abnormal: A continuous or intermittent squealing sound from the condenser fan motor.
You may hear the flow of refrigerant which may create a surging or gurgling sound when the compressor is running and feel warm air blowing from it.
Abnormal: Rattling possibly caused by an improperly placed drain pan.
12. Heat Exchanger (from freezer to compressor)
You may hear the flow of refrigerant which may create a surging or gurgling sound.
Abnormal: Frost or ice forming on it or its covering insulation.
Depending on the placement of the refrigerator in your kitchen, you may want to place a piece of rubber backed carpet beneath the refrigerator and/or mount acoustic tiling or other sound absorbing material around the refrigerator's enclosure to help reduce proliferation of these sounds.
Any of the abnormal sounds listed should be inspected to ensure continued functioning of the appliance and to prevent damage to one of more of the appliance's components.