The refrigerator is making a new noise.
Sub-Zero’s own answer is more generous than most owners expect: banging, buzzing, clicking, rattling, vibration, humming and fan motor noise are all listed as normal operating sounds. So the useful question is never which noise it is making. It is whether the noise is new, whether it is getting louder, and whether the temperature has changed with it. Those three are the whole test, and they come from the maker rather than from us.
On This Page
What the Maker Calls Normal
The first six rows are Sub-Zero describing its own machines. The last two are exceptions that point at a part, and two more are further down, among the four noises that mean something.
| What you hear | What it usually is | Verdict |
|---|---|---|
| Banging, buzzing, clicking, rattling | Normal operating sounds | Sub-Zero lists all of these as normal |
| Vibration, humming, fan motor noise | Normal operating sounds | Same list |
| Gurgling or hissing | Drain tube, defrost drainage or the evaporator | Usually normal operation |
| Sizzling or crackling | Moisture on or near the defrost heater | Normal during a defrost cycle |
| A whoosh as the door closes | Air equalizing through the drain lines | Normal |
| A slight click or creak as a door moves | The spring hinge, on a Classic | Normal |
| A click every few minutes, no cooling | Can be the start relay, not the compressor | Worth a call |
| A knock that started after a repair | On a Monogram, the capillary clip left off | Worth a call |
A gurgle or a hiss is worth singling out, because it sounds like the most alarming thing on the list and is among the least: Sub-Zero attributes it to a partially plugged drain tube, water draining during the defrost cycle, or the evaporator simply working.
The rule that separates them.
Sub-Zero gives one, across two of its answers, and it is worth quoting almost exactly, because it is easy to miss. If the noise is loud, new, louder or more pronounced over time, or if performance or temperatures have been affected, clean the condenser. If it is new, gets louder over time, or does not go away, service may be needed to determine the source.
Read that twice and notice what it does. It puts the condenser before the diagnosis. A coil that cannot shed heat makes the compressor run longer and harder, and a machine running longer and harder is louder without anything being wrong with it. In a valley that spends the summer full of dust, that can explain a refrigerator that got noisier this year and not last. What desert dust does to a condenser.
So the honest sequence is: switch the unit off, clean the coil, switch it back on, wait a day, listen again. If the noise came with a temperature change, or it is still getting worse, that is the moment a visit is worth paying for rather than before.
Four Noises That Mean Something
Against all that normality, four sounds do point somewhere specific, and three of the four are cheaper than they sound.
- 01
A click every few minutes, and no cooling
It can be the start relay rather than the compressor. It is the part that gets the compressor turning, and when it cannot, the control keeps trying. The noise is dramatic and the part is not.
- 02
A knock that began after a repair, on a Monogram
GE’s guide names it: the capillary tube is held against the compressor discharge tube by a clip. Left off when the machine was put back together, it can knock while the compressor runs. A clip, not a compressor.
- 03
A scrape or rattle that comes and goes with the door
It can be the evaporator fan meeting ice that a failed defrost cycle left behind; Sub-Zero lists ice build-up on the fan inside the freezer among the causes of noise. The refrigeration is fine; the blade is not clear. Why the ice is there at all.
- 04
Silence, on a Viking
The opposite problem and the expensive-looking one. A silent Viking can be the inverter, a board or a thermistor that has stopped reporting, not only the compressor, and the control holds the compressor off for at least six minutes between runs. Which is why the compressor is the last thing checked, not the first. What we check, and in what order.
Why it is louder at night.
Because the house is quieter, and Sub-Zero says as much: noises may be more pronounced in an open-concept home, or at night. In a kitchen that opens into a living room, with stone floors and hard surfaces and nothing soft to absorb anything, a machine that was inaudible in a closed 1990s kitchen is simply present.
This matters more here than it sounds, because it can explain a machine that has made the same noise for years and has become unbearable since a remodel. Nothing changed inside the refrigerator. The room stopped hiding it.
The one mechanical thing worth checking in that situation is the grille, which can vibrate against the cabinetry if it is not seated properly, and a run of trim added over it will both trap heat and give a new surface to buzz against. What a remodel does to the fit.
Vibration in a wine cabinet is different.
Everything above is about whether a noise indicates a fault. A wine cabinet adds a second question, because the vibration itself is the damage: hardened compressor mounts and a tired fan bearing pass their vibration straight into the racks, and the wine registers it long before anything shows on a display.
That is the one place on this page where a noise that Sub-Zero would call normal in a refrigerator is worth acting on anyway. Nothing in a kitchen refrigerator minds being shaken. A cellar does. What else a cabinet is quietly telling you.
The visit is $119, waived in full when the repair goes ahead. On a noise, a clean coil can settle it before anyone comes out, which is why the coil comes first.
Questions
Which refrigerator noises are normal?
More than most owners expect. Sub-Zero lists banging, buzzing, clicking, rattling, vibration, humming and fan motor noise as normal operating sounds. It also calls a gurgling or hissing noise usually normal, a whooshing sound as a door closes normal air equalizing through the drain lines, and, on a Classic, a slight click or creak from the hinge as a door moves normal.
So how do I know when a noise matters?
By its history rather than its character. Sub-Zero’s own rule: if the noise is loud, new, louder or more pronounced over time, or if performance or temperatures have been affected, clean the condenser. If it is new, gets louder over time, or does not go away, service may be needed to find the source.
The refrigerator clicks every few minutes. Is that the compressor failing?
Not necessarily. It can be the start relay, the part that gets the compressor turning. A repeated click with no cooling behind it can mean that part is failing, and it is a far smaller repair than the noise suggests.
Why did my Monogram start knocking right after a repair?
GE’s own guide names one cause: a clip holds the capillary tube against the compressor discharge tube, and if it is left off after a repair, a knocking noise may occur while the compressor runs. It is a clip, not a compressor.
My Viking has gone completely silent. Is that worse than a noise?
It is a different search. Silence on a Viking can be the inverter, the high or low voltage board, or a thermistor that has stopped reporting, not only the compressor. The control also holds the compressor off for at least six minutes between runs, so a few minutes of quiet after a power outage can be the machine behaving.
Why does it seem noisier at night?
Sub-Zero says so itself: noises may be more pronounced in an open-concept home, or at night. Nothing about the machine changes after dark; the room around it gets quieter.
Sources
- Sub-Zero, noise from compressor area: banging, buzzing, clicking, rattling, vibration, humming and fan motor noise as normal; the note about open-concept homes and night; and the rule for when to clean the condenser.
- Sub-Zero, refrigerator or freezer noises: sizzling or crackling from moisture on or near a defrost heater, and ice build-up on the fan inside the freezer among the causes of noise.
- Sub-Zero, gurgling or hissing noise: a partially plugged drain tube, drainage during defrost, or evaporator operation, usually normal; and service when a noise is new, gets louder over time, or does not go away.
- Sub-Zero, door makes a wooshing sound: air equalizing through the drain lines.
- Sub-Zero, noisy door hinge: the slight click or creak of a Classic hinge as the door opens or closes, which is normal.
- GE Consumer Home Services technical service guide 31-9091 (2002) for Monogram side-by-side refrigerators: the capillary tube clipped to the compressor discharge tube, and the knock when it is left off.
- Viking Preferred Service manual SMR-0022 for the built-in all-refrigerator VCRB5301 / VCRB5361, May 2012: the inverter and boards, NTC thermistors, and the six-minute compressor dwell before a restart.
Written from these sources and reviewed on (checked again ) by Aphelion Appliance Repair, Phoenix. Figures belong to the series named beside them and series differ, which is why the rating tag settles it. Nothing here is a manufacturer’s instruction, and work inside a sealed system is a technician’s job.
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New noise, and warmer?
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