Sub-Zero Wine Cooler Making Noise: Sorting Hum From Fault

Sounds that mean the unit is doing its job

A wine storage unit runs quieter than a full-size refrigerator, but it is never silent. On Designer IW and Classic BW wine units, and on the UW-24, each zone can be set anywhere from 39°F to 65°F and either one can hold reds or whites, so the system may start up whenever one of the two zones asks for cold. A normal cycle builds, holds steady and fades over several minutes, and none of these needs a repair on its own:

• a steady low hum from the compressor that stops once both zones reach their set points
• a gentle whir from the fans moving chilled air through each zone
• gurgling or a faint hiss as refrigerant flows just after the compressor starts or stops
• small ticks and pops as the liner and racks expand and contract
• a quiet click as the controls switch the compressor or a fan on or off

Noises that point to a failing part

The sounds worth acting on are louder, harsher or more persistent, and where they come from matters as much as the sound itself. Noise inside the cabinet usually involves the evaporator fan behind the rear wall, while noise at the grille, top or bottom, tends to come from the condenser fan, the compressor or something loose in the machine compartment. Our page on loud humming or rattling covers the same sounds in a full-size refrigerator; in a wine unit, watch for these:

• grinding or a tick that keeps time with a fan: a blade striking ice or a shroud, or a worn motor bearing
• squealing or chirping that rises and falls: a dry or corroded fan bearing
• rattling from the base: a loose fastener or trim piece, a shifted drain pan, or a cabinet out of level and vibrating against the millwork
• clinking glass: bottles touching each other or the back wall when the compressor starts
• a loud click, a few seconds of hum, then silence, repeating every few minutes: the compressor trying to start and tripping its overload
• a hum that runs almost nonstop while the wine slowly warms: a system working hard and losing, often because the condenser is matted or its fan has quit

Start with the condenser

The condenser is where the unit sheds the heat it pulls out of your bottles, and once lint, dust and pet hair mat over its fins, the fan and compressor run longer and louder to do the same work. Sub-Zero's guidance is to clean it every six to twelve months, more often in a home with pets, and for a wine unit that has begun running warm it says to clean the condenser if that has not happened within the past three months, then give the unit 24 hours to settle back to temperature. Turn the unit off, remove the grille, and lift the dust with a soft brush attachment moving in the same direction the fins run, because the aluminum bends easily and flattened fins choke airflow as badly as dust. Sub-Zero also says chemical condenser cleaners are unnecessary and not recommended. A house a few blocks from the beach in Cardiff-by-the-Sea is worth checking at the short end of that interval, since salt settles on the coil along with household dust.

Ice maker and water valve sounds on the IW-30CI

Most Sub-Zero wine storage has no ice maker and no water hookup, and Sub-Zero lists its wine units, apart from the IW-30CI, among the products with no internal water filter, so a buzzing water valve or falling ice cannot come from a standard wine column or undercounter unit. The IW-30CI combines wine storage with an ice maker, and its normal noises include a short buzz as the valve opens to refill the mold, a hum while the ejector turns, and a thud as cubes drop into the bin. One ice cube icon on its display means the ice maker is on, and three cubes mean Max Ice is running, which brings more fill and harvest sounds. A valve that buzzes for a long stretch without filling, repeated clicking with no ice, or water on the floor below is a fault rather than a cycle.

When the noise comes with warm bottles

Noise and temperature trouble arriving together usually share one cause. A seized condenser fan lets the compressor overheat and cycle on its overload, and an evaporator fan that grinds and then stops leaves a zone warm while the compressor keeps humming. Allow the 24 hours after a condenser cleaning before you judge the result, and bear in mind that Sub-Zero notes a newly installed wine unit can cool one zone before the other at first. If a zone still drifts from its setting after that, our guide to a wine cooler not holding temperature walks through the next checks. A failing compressor is the most serious possibility, but on a younger unit it may be covered: Sub-Zero's residential sealed system warranty runs five years from original installation and includes parts and labor for a defective compressor, condenser, evaporator, drier and all connecting tubing, under normal residential use.

What to check before you book a visit

A few minutes of careful listening makes a service call quicker and helps separate a loose panel from a mechanical fault, and none of these steps goes further than removing the grille.

• note whether the sound starts inside the cabinet or at the grille, and whether it changes when you open the door
• make a short phone recording of it and note how often it returns
• press gently on the grille and side trim; if the rattle stops, a fastener or trim piece is the cause, not a motor
• shift bottles that touch each other or the rear wall, and check that the cabinet sits level
• copy the model and serial numbers from the rating plate, and our guide to finding the model and serial plate shows where it hides

Getting a noisy wine unit looked at

If the grinding, the start-and-stop clicking or the nonstop running carries on after those checks, the unit needs a technician, because a laboring fan or a compressor that keeps tripping only puts more strain on the rest of the system. We work on Sub-Zero wine storage throughout Cardiff-by-the-Sea, including the Composer District, the Walking District and Poinsettia Heights. Call (858) 703-5919 or use the booking button on this page, and describe the sound, where it seems to come from and the model number so the technician arrives knowing what to look at first.