Sub-Zero · Classic Series
Sub-Zero Classic Series Error Codes
A Classic (BI) built-in warns you with an icon or a short message and keeps the detail as three-part fault codes. Read with the serial era in mind, they usually narrow the search to one part or circuit.
$79 service call, applied to the repair. Monday to Saturday, 8 AM to 7 PM.
In short: the wrench-shaped Service icon tells you how serious it is: steady is minor, flashing is major, flashing with a chime means today. EE replaces the temperature of a section whose sensor failed. Numbered codes such as 40 2 40 stay in memory for a technician. Meanings changed between serial eras, and the tables say where.
Which BI era you have
Sub-Zero kept the BI model numbers through several redesigns while the messages and codes changed. The serial on the tag near the top hinge tells us which version you have.
| Serial era | What it means for codes and messages |
|---|---|
| Before serial 4100000 | The original BI control. Crisper drawer fans and the condenser fan have codes of their own. No LO C, H2 LO or dO Or. |
| Serials 4100000 to 4379999 | The same three-part codes, revised as French door and internal dispenser models arrived; some latest-era changes may already appear here. |
| After serial 4380000 | Documented with LO C, H2 LO and dO Or, codes for variable-speed compressors, stepper valves and the air baffle, and a second water valve. Drawer fan codes are gone. |
These tables are for BI models only.
What the Classic display tells you
| Code or display | What it means | What to do |
|---|---|---|
| Service icon steady | A minor fault was logged, or codes were viewed and never cleared | Not urgent. Book a visit. |
| Service icon flashing | A major fault that can affect temperatures, even if they still look normal | Check the food and call soon. |
| Service flashing with a chime | A section cannot hold temperature, a compressor or water valve relay is stuck, or water is passing the flow meter uninvited | Look for water; if there is any, close the supply valve. Call. |
| EE on the left or right, Service flashing | The freezer (left) or refrigerator (right) compartment sensor or its wiring failed | That compressor falls back to a fixed timer. Watch the food and call. |
| Ice cube and Service icons flashing | Five fills in a row where the water valve stayed on too long; the ice maker is locked out | Check the supply valve and filter. The lockout ends only after the repair. |
| LO C, lights off, keys dead | The panel locked: a door switch reports the door closed while keys are touched, or a door stood open more than five minutes | Close any open door. If it stays locked with every door shut, call: usually the switch or its wiring. |
| H2 LO and three chimes at the dispenser | Over about a gallon in 15 minutes, or the valve on for 150 seconds; dispensing pauses for 45 minutes | A flood guard; wait it out. If it trips often, call. |
| dO Or with a chime | A French door was open more than five minutes with the door alarm switched off | Close it, or see door not closing. |
| Water filter or Pure Air icon | The water filter or the air purifier cartridge is due; a flashing Pure Air icon can also mean its lamp burned out | Replace it and reset the reminder. |
| dE and FL at power-up | A replacement board is still on its default setup, not yet set for your model | A technician step. |
| C and FC for a few seconds | Fault codes were just cleared | The history is gone. |
Displays that are settings rather than faults, such as Sabbath mode or Celsius, are explained on the Classic Series repair page.
How to read a three-part code
A Classic code has three groups: what system, where, and what went wrong. The first number names the system, such as 10 for a temperature sensor or 20 for defrost. The middle character names the place, such as 1 for the refrigerator, 2 for the freezer, or r and F for their cooling coils. The last two digits name the failure, such as 00 for an open circuit or 02 for an unstable reading. So 10 2 02 is a freezer sensor reading unstable. The control keeps the last 50 codes.
Classic fault codes by system
The codes we meet most. Meanings vary by model and serial era; the notes say where.
Temperature sensors
| Code | What it means |
|---|---|
| 10 1 00, 10 1 01, 10 1 02 | Refrigerator compartment sensor open, shorted or unstable. Unstable is most often a connection. |
| 10 2 00 to 10 2 02 | Freezer compartment sensor, the same three faults |
| 10 r 00 to 10 r 02, 10 F 00 to 10 F 02 | Refrigerator or freezer coil sensor; the refrigerator one ends the refrigerator's off-cycle defrost, and both show whether a coil is really cold |
| 10 r 09 | Refrigerator coil reading at least ten degrees warmer than the compartment: a sensor fault, or a coil that really is not cooling |
Relays and board outputs
| Code | What it means |
|---|---|
| 15 1 00, 15 2 00 | Refrigerator or freezer compressor relay stuck open; that compressor gets no power. Flashes with a chime. |
| 15 1 01, 15 2 01 | Compressor relay stuck closed; it never stops and the section can freeze. Flashes with a chime. |
| 15 4 01 | Defrost relay stuck closed, heater on all the time |
| 15 U 01 | Water valve relay stuck closed. Flashes with a chime; close the supply valve. |
| 90 F 38, 90 r 38 | The board's output to a coil fan failed |
| 90 5 01, 90 5 80 to 90 5 99 | Control panel faults: a stuck key, a failed display, lost keypad contact |
| 90 5 38, 90 5 44, 90 5 39 (earlier units) | Main-board outputs: fan power, the glass door heater, the DC fans |
| 90 H 80, 90 H 82 to 90 H 84 | Main board communication or start-up faults; we confirm the code returns before replacing the board |
Freezer defrost
| Code | What it means |
|---|---|
| 20 2 00, 20 2 01 | Defrost terminator stuck open, so the heater never warms, or stuck closed |
| 20 2 05, 20 2 06 | The terminator responds wrongly during defrost: its wiring or mounting |
| 20 2 07 | A defrost part reading out of range; which part depends on the serial era |
| 20 2 50 | Defrost heater open circuit |
Ice maker, water and dispenser
| Code | What it means |
|---|---|
| 30 8 30 | Water went through the flow meter with no call for water. Flashes with a chime: treat it as a leak. |
| 30 8 00 | Fill tube heater circuit open; the fill tube can freeze shut |
| 30 U 00, 30 U 10 | Ice maker or dispenser water valve coil open |
| 30 U 20 | The second water valve, the check valve, open circuit (after serial 4380000) |
| 40 8 40 | The ice maker filled for the longest time allowed and still came up short |
| 50 U 86, 50 U 87 | The flow meter saw slow flow, or none |
| 40 9 40 | The dispenser ran 150 seconds straight: a stuck key or paddle |
| 30 9 86 | The door dispenser chute did not open or close fully, usually ice jammed in it |
Fans, run time and compressors
| Code | What it means |
|---|---|
| 35 F 33, 35 F 34, 35 r 33, 35 r 34 | Freezer or refrigerator coil fan speed out of range. What 33 and 34 mean differs between serial eras, so we test the fan rather than trust the digits. |
| 35 d 36, 35 d 37 | Crisper drawer fan current low or high (before serial 4100000) |
| 40 1 40, 40 2 40 | Refrigerator or freezer compressor ran without a break, four hours or six respectively, five times running. The control forces a defrost and flashes Service; about a day of it adds the chime. |
| 60 1 60, 60 2 60 | The board switched a compressor on and saw no load: its electrical parts or wiring |
| 95 1 25, 95 2 25 | Self-test found a coil that did not get colder with its compressor running |
| 60 1 02, 60 2 02, 60 1 38, 60 2 38 | Lost contact with a variable-speed compressor (after serial 4380000) |
| 40 1 38, 40 2 38, 40 b 38 | Lost contact with a stepper valve or the air baffle (after serial 4380000) |
Heaters and power
| Code | What it means |
|---|---|
| 44 0 00, 44 0 01 | Glass door heater open or shorted; the glass starts to fog |
| 98 0 98 | A brownout: the supply voltage dipped |
What Classic codes turn out to be on a visit
40 2 40 with frost on the freezer back wall
What it usually is: a defrost failure that choked the freezer coil, so the compressor ran for hours. The same history may also hold 20 2 50 or 20 2 00, or a fan speed code from ice around the blade.
What you can check: heavy frost behind the baskets and ice under the drawer. Do not chip at it.
What we do: test the heater and terminator, replace what failed, clear the drain and thaw the coil. See frost buildup.
40 1 40 or 10 r 09 on the refrigerator side
What it usually is: the refrigerator side cannot reach temperature while the freezer is fine. Each side has its own compressor, so the fault sits on the refrigerator's own system; when its coil reads warm with the compressor running, a leak at the refrigerator evaporator moves up the list.
What you can check: the condenser behind the grille, breaker off, and the door closing on its own from halfway.
What we do: clean, check the fan and door, read the coil live, and only then measure the sealed system. Our July 2026 job in Irvine, Sub-Zero Refrigerator Not Cooling? Evaporator Leak Fix, shows what an evaporator leak repair involves.
Ice maker locked out, with 40 8 40 or 50 U 86
What it usually is: water arriving too slowly. The Classic times every fill. Each fill that runs too long shuts the ice maker off for a day, and after five in a row it stays off until it is repaired. The flow meter code tells us whether the water came slowly or not at all.
What you can check: the supply valve fully open, the filter not overdue, no kink in the line.
What we do: measure flow, test the valves and flow meter, replace what failed and clear the lockout. See ice maker not working and water dispenser not working.
Clearing and silencing on a Classic
Codes stay in memory until we clear them as the last step of the repair; C and FC on the display confirm it. Do not hold the ALARM key to stop a chime: a long press erases the history we need. A major alarm can be quieted for a day without losing the codes; call and we will talk you through it.
Stay safe. If the Service icon flashes with a chime and there is water at the base, close the water supply valve to the refrigerator before anything else. If you clean the condenser, turn the breaker off first. Leave the diagnostic keys alone.
What a Classic repair costs
The $79 service call covers the trip and diagnosis, fault history included, and is applied to the repair once you approve the written price. Typical built-in refrigerator repair ranges:
Built-in refrigerator and freezer repair (Sub-Zero, Thermador, Viking, Monogram, Miele)
| Repair | Typical price, parts and labor |
|---|---|
| Condenser cleaning and performance check | $150 to $250 |
| Condenser fan motor | $350 to $600 |
| Evaporator fan motor | $350 to $650 |
| Temperature sensor (thermistor) | $250 to $450 |
| Defrost heater or defrost termination | $350 to $650 |
| Water valve | $300 to $550 |
| Door gasket, per door | $300 to $600 |
| Door hinge or closer cam | $300 to $650 |
| Ice maker assembly | $450 to $900 |
| Electronic control board | $650 to $1,300 |
| Refrigerant leak repair and recharge | $900 to $2,000 |
| Evaporator replacement | $1,200 to $2,500 |
| Compressor replacement (sealed system) | from $2,000 |
Typical Orange County ranges for parts and labor. The $79 service call is applied to any of them. Parts that ship from the manufacturer and older or discontinued models can run higher. You get the exact written price after the diagnosis and before any work starts.
See the pricing page, the Sub-Zero error codes overview for other lines, the Service light and alarm beeping pages, or Sub-Zero repair.
Talk to the technician first
Monday to Saturday, 8 AM to 7 PM. The $79 service call is applied to the repair.
Sub-Zero Classic error codes: questions
What does 10 2 02 mean on my Sub-Zero?
The freezer compartment sensor is reading unstable. It is most often a loose or corroded connection rather than a dead sensor; minor, but worth fixing before it becomes EE.
What does LO C mean on a Sub-Zero BI refrigerator?
The control panel locked itself: a door switch says the door is shut while keys are touched, or a door stood open more than five minutes. If it stays locked with every door closed, the switch or its wiring usually needs replacing.
Why does my Sub-Zero dispenser say H2 LO?
Over a gallon went out in 15 minutes, or the water ran 150 seconds, so the dispenser paused for 45 minutes. Normal after filling a big pot; if it trips in ordinary use, the valve or flow meter needs a look.
What does 30 8 30 mean?
Water passed the flow meter when nothing called for it, which can mean a valve leaking through. Close the water supply valve, check under the unit, and call.
What does 15 U 01 mean on my Sub-Zero?
The board relay that powers the water valve is stuck closed, so water can keep flowing, and Service flashes with a chime. Close the water supply valve to the refrigerator and call; the board needs testing.
How do I clear a fault code on a Sub-Zero Classic?
Leave it for the visit. Codes are cleared once the cause is fixed, and C and FC on the display confirm it. Cleared earlier, the fault comes back with no history to diagnose it from.
Do these codes apply to the newer CL Classic models?
Not directly. The CL generation has its own service documentation, so we read its faults against that. We repair both, as an independent service not affiliated with Sub-Zero Group.