Refrigerator lights out, and the cold stayed.
When a built-in refrigerator stays cold with its lights out, look at a mode, a cutoff, then the light circuit. On a Sub-Zero 600 or Classic (BI), Sabbath Mode turns the lights off while cooling carries on, and a door left open can trip a light terminator that keeps them off until the door has stayed shut 45 minutes.
Viking’s manual answers “unit running and no lights” with Sabbath Mode first. A Monogram ZIS gives its lights their own circuit, with a master switch, two breakers and two heat cutoffs, so dark lights there say nothing yet about the cooling.
On This Page
What Does Each Sign Mean?
The display, the door and the series narrow it down. The last column names the source of each row.
| What you see | Maker and series | Likely cause | Owner step, or a visit | Source |
|---|---|---|---|---|
| Lights out, the display faint or showing SAb, still cold | Sub-Zero 600 Series; Classic (BI) | Sabbath Mode | Press UNIT ON/OFF (600) or touch POWER (BI) once. A 600 that switches off instead was not in Sabbath Mode | Sub-Zero 600 and BI Sabbath answers; 600-2 manual, p. 3-17 |
| Lights dim, and on with the door shut | Sub-Zero Classic (CL), Designer, PRO 36 and 48 | Sabbath Mode, as designed | Hold the Sabbath icon, or wait: CL, DET, DEC and PRO end it after 74 hours | Sub-Zero Sabbath answers by series |
| One section dark after its door stood open | Sub-Zero 500, 600, 700 Series, IC-27 | The light terminator | Keep the door shut 45 minutes | Sub-Zero light terminators; 600-2 manual, p. 8-18 |
| Both sections dark, keys show L OC | Sub-Zero Classic (BI) made from December 18, 2009 | The light terminator, after 15 minutes open | Door shut 45 minutes, or the breaker off and on | Sub-Zero light terminators |
| Lights and display both dark, still cold | Sub-Zero 600, Classic (BI), IC-27 | Bulbs or the switch: the display is backlit by the interior bulbs | Test the switch, then try new bulbs | Sub-Zero backlighting and lights-out answers |
| Running, no lights, SAB on the display | Viking VCRB5301 / VCRB5361 | Sabbath Mode; without SAB, a bulb or an open circuit | ACTIVATE CONTROLS and DISPLAY OFF together, three seconds. Wiring is a visit | Viking manual, pp. 9, 39 |
| Dark on both sides, or on one | Monogram ZIS side-by-side | Both: the master light switch on the 2002 ZIS, Sabbath Mode on a current one. One: that side’s door switch, breaker, heat cutoff or transformer | Sabbath Mode off, or the door shut while the lamps cool; then a technician’s check | GE service guide 31-9091, pp. 44–46; owner’s manual 49-1000362, p. 15 |
| Lights on at full brightness, door shut | Sub-Zero 600 Series | A door not closing, the switch depressor, a failed switch | Door open, push the switch in and out: the lights should follow | Sub-Zero 600 lights answer; 600-2 manual, p. 8-18 |
The series decides every row, and the rating tag names it: find your model number · which Sub-Zero series it is.
Is It Sabbath Mode?
Sabbath Mode, made for the Sabbath and religious holidays, keeps a door from switching the lights and other features on. Depending on the model, Sub-Zero says, the lights go off or hold a constant dim while cooling runs on, and Sub-Zero and GE both say a unit returns to it after an outage.
- 01
Sub-Zero 600, 700, Classic (BI) and 648PRO: dark, still cooling
Lights, ice maker and door alarm go off while cooling carries on. A 600 shows its temperatures faintly, a Classic (BI) shows SAb, and a 648PRO chimes four times and darkens its external displays. To leave: UNIT ON/OFF once on a 600 or 700, POWER on a Classic (BI), Power twice on a 648PRO. A 600 that switches off at the key was never in Sabbath Mode. Its fan still stops when a door opens; Sub-Zero suggests taping the fan switch down for the Sabbath, then removing the tape to prevent performance issues.
- 02
Classic (CL), Designer and PRO: dim lights that stay on
These keep the lights on at reduced brightness, door open or shut. Classic (CL), Designer (DET, DEC) and PRO models end Sabbath Mode after 74 hours, or when the Sabbath icon is held 10 seconds, three on a PRO. Designer IT, IC and ID models leave it when the screen is held five seconds, or POWER about ten on updated controls. The Owner’s App can start Sabbath Mode on Classic and Designer units but not end it.
- 03
Viking VCRB: SAB, and a memory
ACTIVATE CONTROLS and DISPLAY OFF, held together three seconds, bring three beeps and a display blank but for SAB. The lights stay off, and alarms are suppressed but recorded. The same two pads end it, and any recorded alarm is then shown and sounded.
- 04
Monogram: a switch, or a mode
On the 2002 ZIS side-by-side, GE’s service guide calls the master light switch behind the grille panel the Sabbath switch; off, it darkens both compartments. The current built-in side-by-sides have a Sabbath Mode of their own: two freezer pads held five seconds, SA on the display, then the display and lights off, the door alarms and the ice maker disabled, until the same pads end it or 96 hours pass. GE’s page for the older 30-inch integrated bottom-freezer holds alarm and + five seconds.
Star-K compliance, Sub-Zero notes, takes strict adherence to Star-K’s guidelines. Classic, Designer, PRO 36 and 48 and 648PRO models comply as standard; the 600 and 700 Series and 400 Series wine storage need a kit, which Sub-Zero recommends a technician install and its warranty does not cover. Units built before Star-K’s serial breaks cannot comply, and the 500 Series has no Sabbath Mode.
Did a door stand open too long?
Then the lights may only be cooling off. Lights left on get very hot, Sub-Zero notes, so it fits a light terminator, a safety cutoff that turns them off after an extended time on; on most models that have one, the control panel stops responding meanwhile.
On the 500, 600 and 700 Series and the IC-27, only the open section loses power; the 650 has no terminator in its freezer. Keep the door shut 45 minutes and, as the terminator cools, lighting and operation return. The 600-2 manual puts a terminator in each compartment’s lighting circuit, between the door’s light switch and the lamps.
A Classic (BI) made before December 18, 2009 works the same way, and ignores its keys until the lights return. Made later, it darkens both sections once a door has stood open 15 minutes and keeps them dark for 45 minutes after it closes; keys pressed meanwhile show L OC, and the breaker, switched off and on, skips the wait.
Designer IT, IC and ID models dim their LEDs to 30% after 10 minutes open and restore them after 10 minutes shut; a PRO dims its lights after three minutes and counts 180 seconds down on the display. Switching a compartment off changes none of this, Sub-Zero adds.
Is It the Switch or a Bulb?
With no mode set and no door left open, the makers turn to the parts behind the light.
- 01
The light switch
On Classic, 700, 600, 500, 400 and 200/300 Series units, Sub-Zero’s test is to wiggle the light switch and push it in and out. It sits in the top mainframe above the door, or low, above the grille, on a 501 or 601; on other 600s it is the left of two, beside the fan switch. A freezer’s switch may be frozen: defrost if possible, and never lubricate it.
- 02
The bulbs, and a dark display
On a 600, Classic (BI) or IC-27 the display is backlit by the interior bulbs, so a dark display with dark lights can be bulbs alone; the control, Sub-Zero says, works normally with a bulb out. A 600 takes 40-watt A15 appliance bulbs, sold locally; Sub-Zero advises nothing stronger, though the original may be 75 watts. Classic (BI) bulbs are blue-tinted, from Sub-Zero’s parts distributors.
- 03
Changing one safely
Power off at the breaker first: GE notes that voltage reaches the socket whenever a door is open, and a broken bulb leaves the live parts bare. For a broken bulb, Sub-Zero rules out WD-40 or any lubricant in the socket and suggests needle-nose pliers, or half a potato pressed over the base. A 600’s diffuser must lock back onto its posts or it can drop; one left off is on Sub-Zero’s list for food freezing.
- 04
On a Viking, the switch behind the grille
A Viking VCRB’s power switch behind the top grille is there for cleaning and bulb changes, and Viking asks that it be back ON afterward. Its 40-watt bulbs sit at the top of the cabinet behind a light cover.
Still dark with good bulbs and a switch that moves freely? Sub-Zero’s answer is service. What we repair on a Sub-Zero · on a Viking.
How does a Monogram light its cabinet?
In GE’s 2002 service guide, a Monogram ZIS side-by-side lights its compartments with 12-volt halogen lamps, 170 watts in the fresh-food side and 70 in the freezer, fed by two transformers under the refrigerator, one per compartment. Each side has its own door switch, resettable breaker and temperature overload device, which opens when a door left open lets the lamps overheat and closes again at 90°F. Turning the temperature control OFF, GE notes, does not cut power to the lights.
So both sides dark fits the one switch that darkens both: the master light switch behind the grille panel, which GE calls the Sabbath switch and turns off for every bulb change. One side dark points to that side’s switch, breaker, overload device or transformer, all checks GE’s guide makes with a meter. On a current built-in side-by-side, the owner’s manual adds a Sabbath Mode that keeps the lights and the display off until it is ended, or for 96 hours.
The lamps run hot, and GE warns that every shield and lamp protector must go back, or their heat can damage the refrigerator. Its flowchart for a dead Monogram starts with the interior lights, so a dark ZIS that is still cold is not a refrigerator that has stopped. What we repair on a Monogram.
Why do the lights stay on with the door shut?
Rule out the mode first: in Sabbath Mode, dim lights behind a closed door on a Classic (CL), Designer or PRO are the design. Bright lights that burn on warm the cabinet, and Sub-Zero lists intermittent warm temperatures with this symptom. Its steps: clear whatever keeps the door from closing, press the switch firmly, then turn the breaker off for 30 seconds and retest.
On a 600 other than the 601R and 601F, a depressor at the top center of the door presses the switch; with the door open, push the switch in and out, and if the lights do not follow, Sub-Zero says the switch has failed. GE checks that the light goes out with the door closed among its first steps for a warm Monogram fresh-food side.
The door alarm reads the same switch. Refrigerator beeping, and the door looks shut · what a light left on does to a freezer.
What about accent lights?
Some lights are meant to stay on. On the 600-2 glass-door models, the 601RG-2, 611G-2 and 650G-2, the LIGHTS ON/OFF key runs three 15-watt light strips that stay lit with the door closed, and Sub-Zero’s first step for 600 Series lights that will not go out is to make sure they are not the ones lit.
Strips that stay dark with the key on point to their wiring, the control board, a strip or the membrane switch, and reaching one means removing the light diffuser, the evaporator cover and the fan shroud: a technician’s job. On a PRO 36 or 48 the accent lighting is the interior lighting, set under Settings, Lights to HI, MED, LO or OFF.
When is it a visit?
When the lights stay dark after the mode, the wait, the switch and the bulbs. Then the 600-2 manual traces 115 volts from the sockets back to the control board and tests its output; Viking’s table ends at an open circuit, with the lights switched by a relay on the high-voltage board; GE’s chart ends at a transformer or an open circuit to the lamps.
Some lights are service parts from the start: Designer LEDs, PRO lighting, and the light switches in Designer, Classic (CL), PRO and Undercounter models, Sub-Zero says; GE says the same of LED assemblies. Write down anything else the display shows first: what each code means.
The visit is $119, waived in full when you go ahead with the repair, and the work is a fixed price approved before any repair begins. Still inside the maker’s warranty? Call the maker first. What we repair on a Sub-Zero · on a Viking · on a Monogram.
Call (478) 888-2999, every day, 7am–6pm, and tell us the make and what happened.
Questions
Why are the lights out in my Sub-Zero when it is still cold?
After power, Sub-Zero’s own list names Sabbath Mode, which turns the lights off on a 600 Series or Classic (BI) while cooling carries on, and the light terminator, which cuts them after a door stands open and brings them back once it has stayed shut 45 minutes. Then the light switch, which can stick, or freeze in a freezer, and the bulbs.
How do I turn off Sabbath Mode on a Sub-Zero?
By series. A 600 or 700 Series: press UNIT ON/OFF once. A Classic (BI): touch POWER. A 648PRO: touch Power twice. A Classic (CL) or Designer (DET, DEC): hold the Sabbath icon 10 seconds; a PRO 36 or 48: three seconds. The CL, DET, DEC and PRO also end it by themselves after 74 hours. The Owner’s App can start Sabbath Mode but cannot end it.
What does L OC mean on a Sub-Zero with the lights out?
On a Classic (BI) made from December 18, 2009 on, L OC means keys were pressed while the light terminator had the lights off. It trips once a door has stood open 15 minutes, and the lights stay off for 45 minutes after it closes. Wait with the door shut, or switch the breaker off and on to skip the wait.
Why do my refrigerator lights stay on with the door closed?
On a Sub-Zero Classic (CL), Designer or PRO in Sabbath Mode, dim lights behind a closed door are the design. Otherwise Sub-Zero looks at the door and the switch: clear whatever stops the door closing, press the switch firmly, then turn the breaker off for 30 seconds. On a 600 Series, check the depressor at the top center of the door. A light that burns on warms the cabinet.
Sources
- Sub-Zero, interior lights turned off: power, faint temperatures and Sabbath Mode, the light terminator, where the switch sits, a frozen switch, no lubricant. Its interior lights do not turn off answer: warm temperatures, the causes, the three steps.
- Sub-Zero, light terminators: the safety feature, one section on the 500, 600, 700 and IC-27, none in the 650 freezer, 45 minutes, the Classic (BI) by build date, 15 minutes, L OC and the breaker, the Designer’s 30%, and disabled zones.
- Sub-Zero, Sabbath Mode and Star-K information: lights off or dim by model, the return after a power failure, Star-K as standard or by kit, the 500 Series without it. Its accessory kit answer: normal cooling, serial breaks, a technician, installation outside the warranty.
- Sub-Zero Sabbath Mode answers by series: 600 Series, 700 Series, Classic (BI), Classic (CL), Designer (DET, DEC), Designer (IT, IC, ID), PRO 36 and PRO 48, 648PRO and the Owner’s App.
- Sub-Zero lighting answers: 600 Series lights not turning off, light switch replacement, control backlighting, 500 and 600 Series bulbs, Classic (BI) bulbs, 600 Series diffuser, Designer lighting, PRO lighting and broken or hard-to-remove bulbs.
- Sub-Zero Built-In (600-2) Series technical service manual (Job Aid #3758407, 2005): accent lighting (pp. 3-5, 3-7), power to the lighting and the light terminators (p. 3-8), Sabbath Mode (p. 3-17), the light and fan switches (p. 7-6), the accent strips (p. 7-21), and troubleshooting rows W and X (p. 8-18) and Y (p. 8-19).
- Viking Preferred Service manual SMR-0022, VCRB5301 / VCRB5361 all-refrigerator, May 2012: the power switch behind the top grille (p. 6), Sabbath Mode (p. 9), the bulbs (p. 21), the light relay (p. 37), and “unit running and no lights” (p. 39).
- GE Consumer Home Services technical service guide 31-9091 (2002), Monogram ZIS360, ZIS420 and ZIS480: the master light switch (p. 9), the compartment lights and their diagnostic (p. 44), door switches, the Sabbath switch and the overload devices (p. 45), breakers, transformers and bulbs (p. 46), bulb replacement (pp. 47, 48), “Fresh Food Warm – Freezer Normal” (p. 53) and “Refrigerator Dead – No Sound, No Cooling” (p. 58).
- GE Appliances, Monogram Sabbath Mode feature: the return after an outage. Its 30-inch integrated bottom-freezer page: alarm and +, five seconds, the main light switch locked.
- GE Appliances, Monogram built-in side-by-side owner’s manual 49-1000362 (Rev. 8), from the ZISB420DNII support page: Sabbath Mode, what it disables, and the exit after 96 hours (p. 15).
- GE Appliances, selecting appropriate light bulbs (voltage at the socket with the door open) and interior LED lighting (LED assemblies need a service technician).
Written from these sources and reviewed on (checked again ) by Aphelion Appliance Repair, Phoenix. Modes, key sequences and timings belong to the series named beside them, and other series differ. Nothing here is a manufacturer’s instruction.
Read Next
- Refrigerator beeping, and the door looks shutThe door alarm reads a switch, not the door. What each beep means on a Sub-Zero, Viking or Monogram, why silencing fixes nothing, and Sabbath Mode.
- Not cooling at all, before anyone says compressorWarm on both sides, or silent: what the three makers check first, and why the compressor comes late, if at all.
- Freezer warm, refrigerator perfectA Sub-Zero freezer has its own system; a Monogram shares one. The makers’ checks, in order, from their manuals.
- Which Sub-Zero series do you have?Classic was Built-In, Designer was Integrated, and the model on the tag decides whose answer applies.
Dark inside, still cold?
Tell us the make, what the display shows and how long a door stood open. We answer every day, 7am–6pm.