Sub-Zero control panel showing a diagnostic readout

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Sub-Zero Refrigerator Error Codes & Service Mode Guide

Search any Sub-Zero fault code for 600/700 and Built-In (BI) models — refrigerator, freezer and wine units — learn what it means, and find out whether it's a quick reset or a service call.

How Sub-Zero error codes work

When a Sub-Zero detects an abnormal reading — a sensor out of range, a defrost cycle that didn't complete, a compressor running too long — its control board stores a numeric fault code and often lights a SERVICE indicator. Reading those codes in diagnostic mode is the fastest way to know which subsystem is failing before any parts are touched.

This page is a complete, searchable reference for 142 documented codes across two control generations: the legacy 600/700 series and the modern Built-In (BI) control board. Use the search box below to jump straight to your code.

How to read codes in service mode

  1. Locate the control panel. Find the digital control panel inside the fresh-food compartment (built-in models) or behind the upper grille.
  2. Enter diagnostic mode. On most built-in models, press and hold a combination of panel keys (commonly involving the on/off and a temperature key) for about 5 seconds until the display changes. The exact sequence varies by model and generation.
  3. Read the stored codes. The panel cycles through any stored fault codes. Note every code shown, including the model series prefix.
  4. Match the code below. Search the code in the table on this page to see what subsystem it points to — thermistor, defrost, compressor run time, icemaker, fan or control board.
  5. Clear and verify. After a repair, clear the code and run the unit to confirm it does not return. A recurring code means the underlying fault is still present.

Comfortable doing the diagnosis but not the repair? Book a Bay Area technician and share the codes you found — we'll arrive prepared with the right parts. See also how to enter Sub-Zero service mode and, for cooking appliances, our Wolf and Viking error-code guides.

Most-searched codes

Jump straight to the codes people look up most

These are the Sub-Zero faults we get asked about most often. Tap one to go to its full explanation, or search the complete list below.

Searchable reference

Sub-Zero error code lookup

All 142 documented codes

05 600/700 Refrigerator Cabinet Thermistor read open or shorted for 10+ seconds, or repeatedly read erratic temperatures
06 600/700 Refrigerator Evaporator Thermistor read open or shorted for 10+ seconds, or repeatedly read erratic temperatures
07 600/700 Freezer Cabinet Thermistor read open or shorted for 10+ seconds, or repeatedly read erratic temperatures
08 600/700 Freezer Evaporator Thermistor read open or shorted for 10+ seconds, or repeatedly read erratic temperatures
20 600/700 Defrost under-heat with no voltage feedback through gray/white wire at defrost start
21 600/700 Defrost overheat
22 600/700 No voltage feedback through gray/white wire at defrost start
23 600/700 Defrost overheat with no voltage feedback through gray/white wire at defrost start
24 600/700 Defrost under-heat
30 600/700 Excessive icemaker water valve solenoid activation (exceeded 15 seconds, 5 times)
40 600/700 Excessive freezer compressor run
50 600/700 Excessive refrigerator compressor run
10 1 00 BI Refrigerator Cabinet Thermistor Open. Check ohms and verify temperature readings.
10 1 01 BI Refrigerator Cabinet Thermistor Shorted. Check ohms and verify temp. readings.
10 1 02 BI Refrig. Cabinet Thermistor Unstable. Check for bad connections / damaged wires.
10 2 00 BI Freezer Cabinet Thermistor Open. Check ohms and verify temperature readings.
10 2 01 BI Freezer Cabinet Thermistor Shorted. Check ohms and verify temperature readings.
10 2 02 BI Freezer Cabinet Thermistor Unstable. Check for bad connections / damaged wires.
10 3 00 BI Condenser Thermistor Open. Check ohms and verify temperature readings.
10 3 01 BI Condenser Thermistor Shorted. Check ohms and verify temp. readings.
10 3 02 BI Condenser Thermistor Unstable. Check ohms and verify temperature readings.
10 7 00 BI Ambient Thermistor Open. Check ohms and verify temperature readings.
10 7 01 BI Ambient Thermistor Shorted. Check ohms and verify temperature readings.
10 7 02 BI Ambient Thermistor Unstable. Check ohms and verify temperature readings.
10 F 00 BI Freezer Evaporator Thermistor Open. Check Ohms and verify temperature Readings.
10 F 01 BI Freezer Evaporator Thermistor Shorted. Check Ohms and verify temp. Readings.
10 F 02 BI Freezer Evaporator Thermistor Unstable. Check for bad connections / damaged wires.
10 r 00 BI Refrigerator Evaporator Thermistor Open. Check Ohms and verify temp. Readings.
10 r 01 BI Refrigerator Evaporator Thermistor Shorted Check Ohms and verify temp. Readings.
10 r 02 BI Refrig. Evaporator Thermistor Unstable. Check for bad connections / damaged wires.
10 r 09 BI Refrig. Evaporator thermistor read higher than cabinet thermistor by at least ten (10) degrees. Error may indicate problem with thermistor or a unique evap related problem.
15 1 00 BI Refrigerator Compressor Relay stuck open. No power to Compressor. Verify, replace control board.
15 1 01 BI Refrigerator Compressor Relay is stuck closed. Power to compressor at all times. Verify, replace control board.
15 2 00 BI Freezer Compressor Relay stuck open. No power to Compressor. Verify, replace control board.
15 2 01 BI Freezer Compressor Relay is stuck closed. Power to compressor at all times. Verify, replace control board.
15 4 00 BI Defrost Relay is stuck open. No power to defrost heater. Verify, replace control board.
15 4 01 BI Defrost Relay stuck closed. Power to defrost heater at all times. Verify, replace control board.
15 8 00 BI Icemaker Relay is stuck open. No power to icemaker. Verify, replace control board.
15 8 01 BI Ice Maker Relay stuck closed. Power to icemaker at all times. Verify, replace control board.
15 8 10 BI Ice Accessories Relay is stuck open. No power to ice accessories (fill tube heater, mullion heater). Verify, replace control board.
15 8 11 BI Ice Accessories Relay is stuck closed. Power to ice accessories (fill tube heater, mullion heater) at all times. Verify, replace control board.
15 9 00 BI Dispenser Auger Relay stuck open. No power to auger. Verify, replace control board.
15 9 01 BI Auger Relay is stuck closed. Power to auger at all times. Verify, replace control board.
15 9 65 BI Water Valve Selecting Relay stuck at Dispenser water position. Ice making system disabled. Replace control board.
15 9 66 BI Water Valve Selecting Relay stuck at Icemaker water position. Replace control board.
15 L 00 BI Main Lights Relay stuck open. Power to lights at all times. Verify, replace control board.
15 L 01 BI Main Lights Relay is stuck closed. No voltage to lights. Verify, replace control board.
15 U 00 BI Water Valve Relay is stuck open. No power to water valve. Verify, replace control board.
15 U 01 BI Water Valve Relay is stuck closed. Power to water valve at all times. Verify, replace control board.
15 U 10 BI Water Check Valve Relay is stuck open. No power to check valve. Verify, replace control board.
15 U 10 BI Water Check Valve Relay is stuck closed. Power to water valve at all times. Verify, replace control board.
20 2 00 BI Defrost Bi-metal stuck open. Verify the bi-metal is open circuit below 40°F (4°C). Replace if necessary.
20 2 01 BI Defrost Bi-metal stuck closed. Verify the bi-metal is closed above 70°F (21°C). Replace if necessary.
20 2 05 BI Mis-wired Bi-metal. Normal temps during defrost, but inappropriate response from bi-metal. Check wiring and bi-metal mounting.
20 2 06 BI Mis-wired Bi-metal. High temps during defrost, and inappropriate response from bi-metal. Check wiring and bi-metal mounting.
20 2 07 BI Defrost Bi-metal Error - Check Bi-metal ohms. Replace heater if necessary.
20 2 50 BI Defrost Heater Open. Verify wiring and heater. Check heater ohms. Replace heater if necessary.
30 8 00 BI Ice accessories open circuit. Check wiring for fill tube heater (and mullion chute heater, if equipped).
30 8 05 BI No signal from icemaker for fill. Check wiring and power to ice maker.
30 8 10 BI Icemaker open circuit. Check power and wiring to icemaker.
30 8 30 BI Water valve not opened but water observed passing through.
30 9 01 BI Bulk Ice Switch stuck closed. Bulk ice switch pressed/closed for >5 seconds with door closed.
30 9 10 BI Dispenser auger open. Check wiring and power to auger motor. Check auger ohms.
30 9 80 BI Check communications cable to dispenser.
30 9 86 BI Chute motor timed out. Chute motor failed to reach open or closed position. Verify motor and chute are moving freely and not jammed or blocked. Replace dispenser assembly if necessary.
30 U 00 BI Water valve open. Check wiring and power to water valve. Check solenoid ohms.
30 U 10 BI Dispenser water valve open. Check wiring and power to water valve. Check solenoid ohms.
30 U 20 BI Water Check Valve open circuit. Solenoid is open.
35 A 36 BI Check air filter fan is connected properly and functioning.
35 A 37 BI Check air filter fan is connected and no shorts are evident.
35 F 33 BI Check Freezer evap. fan for obstructions that cause inability to achieve full speed.
35 F 34 BI Verify Freezer evaporator fan not shorted - the fan is running faster than its setting.
35 r 33 BI Check Refrigerator evap. fan for obstructions that cause inability to achieve full speed.
35 r 34 BI Verify Refrig. evaporator fan not shorted - the fan is running slower than its setting.
40 1 38 BI Refrigerator stepper valve communication fault. Replace control board.
40 1 40 BI Excessive Refrigerator run time. Verify performance of unit and check for door leaks, door ajar, proper charge in system, and icing of evap.
40 2 38 BI Freezer stepper valve communication fault. Replace control board.
40 2 40 BI Excessive Freezer run time. Verify performance of unit and check for door leaks, door ajar, proper charge in system, and icing of evap.
40 8 40 BI Icemaker ran for maximum fill time without achieving necessary volume. Check for water system blockages, kinked water lines, proper water pressure to unit.
40 9 40 BI Dispenser active for maximum fill time. Water was dispensed for 150 seconds. Verify no stuck keys or flooding.
40 b 38 BI Baffle stepper communication fault. Replace control board.
44 0 00 BI Glass door heater open circuit. Check wiring and power to heater. Check heater ohms.
44 0 01 BI Glass door heater short circuit. Check wiring and power to heater. Check heater ohms.
44 9 42 BI 1 watt glasswell heater not detected. Check wiring and power to heater. Check heater ohms.
44 9 43 BI 4 watt glasswell heater not detected. Check wiring and power to heater. Check heater ohms.
45 1 00 BI Main Refrigerator lights open circuit. Check lights and wiring.
45 2 00 BI Main Freezer lights open circuit. Check lights and wiring.
45 1 01 BI Main Refrigerator lights short circuit. Check lights and wiring.
45 2 01 BI Main Refrigerator lights short circuit. Check lights and wiring.
45 A 45 BI Air filter light burned out. Replace air filter cartridge.
45 L 00 BI Accent lights open circuit. Check lights and wiring.
45 L 01 BI Accent lights short circuit. Check lights and wiring.
50 U 80 BI Water Flow meter not detected. Verify power and wiring to flow meter assembly. If power and wiring are OK, replace flow meter assembly.
50 U 86 BI Water Flow meter detected low flow. Verify water pressure and check for any water system obstructions.
50 U 87 BI Water Flow meter did not detect flow. Verify water pressure, water flow, and that meter is not blocked or dirty.
60 1 02 BI Refrigerator variable speed compressor communication error. Replace control board.
60 1 38 BI Refrigerator variable speed compressor communication error. Replace control board.
60 1 60 BI No Refrigerator compressor load detected. Check compressor electricals and wiring.
60 2 02 BI Freezer variable speed compressor communication error. Replace control board.
60 2 38 BI Freezer variable speed compressor communication error. Replace control board.
60 2 60 BI No Freezer compressor load detected. Check compressor electricals and wiring.
90 0 70 BI Flash Failure. Reconfigure control board. Replace control board if reconfigure fails.
90 0 71 BI Flash Failure. Reconfigure control board. Replace control board if reconfigure fails.
90 0 72 BI Flash Failure. Reconfigure control board. Replace control board if reconfigure fails.
90 0 73 BI Flash Failure. Reconfigure control board. Replace control board if reconfigure fails.
90 0 74 BI Flash Failure. Reconfigure control board. Replace control board if reconfigure fails.
90 0 75 BI Flash Failure. Reconfigure control board. Replace control board if reconfigure fails.
90 0 81 BI Microcontroller fault. Replace control board if fault is active.
90 0 90 BI Microcontroller fault. Replace control board if fault is active.
90 0 92 BI Microcontroller fault. Replace control board if fault is active.
90 0 93 BI Microcontroller fault. Replace control board if fault is active.
90 3 55 BI Condenser fan triac Open. Verify condenser fan operation. Replace control board if fault is active.
90 3 56 BI Condenser fan triac shorted. Verify condenser fan operation. Replace control board if fault is active.
90 5 01 BI Key shorted or damaged on Control Panel. Verify key performance. Replace Control Panel.
90 5 38 BI 12V Fan power output fault. Verify constant 12V DC to evaporator fan. Replace control board if fault is active.
90 5 44 BI Glass door heater output fault. Check wiring and power to heater. Replace control board if fault is active.
90 5 80 BI No keypad communications. Check wiring and key performance of Control Panel.
90 5 85 BI User display failure. Replace Control Panel.
90 5 95 BI Key shorted or damaged on Control Panel. Verify key performance. Replace Control Panel.
90 5 96 BI Key shorted or damaged on Control Panel. Verify key performance. Replace Control Panel.
90 5 97 BI Control Panel microcontroller problem. Verify key performance. Replace Control Panel.
90 5 99 BI Control Panel error. Verify key performance. Replace Control Panel.
90 9 80 BI No communications with door dispenser. Check proper model configuration. Check wiring to dispenser.
90 A 38 BI Air filter fan output fault on control board. Replace control board if fault is active.
90 b 80 BI No stepper micro communication. Replace control board.
90 F 38 BI Freezer evap fan output fault on control board. Verify if fan is working. Replace control board if fault is active.
90 H 80 BI Communications problems on main board. Replace control board.
90 H 82 BI Intermittent communications on main board. Replace control board.
90 H 83 BI Communications problems on main board. Replace control board.
90 H 84 BI Initialization fault. Power unit OFF, then ON, and verify if code remains active. Replace control board if fault is active.
90 L 38 BI Check if accent lights are working. Replace control board if fault is active.
90 r 38 BI Refrigerator evaporator fan output faulted. Verify fan operation. Replace control board if fault is active.
95 1 25 BI Verify Refrigerator evaporator is cooling properly when compressor is on. Check sealed system charge if not.
95 2 25 BI Verify Freezer evaporator is cooling properly when compressor is on. Check sealed system charge if not.
95 1 00 BI Refrig. compressor microprocessor pin stuck in off position. Replace control board.
95 1 01 BI Refrig. compressor microprocessor pin stuck in on position. Replace control board.
95 2 00 BI Freezer compressor microprocessor pin stuck in off position. Replace control board.
95 2 01 BI Freezer compressor microprocessor pin stuck in on position. Replace control board.
98 0 98 BI Brownout conditions were detected.
d0 0r BI Door Ajar Alarm is off; door is left open more than 5 minutes; audible alarm chimes. Alarm stops when door is closed. A 5 minute UIM time out (no response from UIM) follows the closing of the door.
H2 L0 BI Over 1 gallon of water dispensed within 15 minutes, or water valve energized 150 seconds. “H2 LO” displayed for 5 seconds and 3 chimes are emitted when water paddle pressed. Dispensing interrupted for 45 minutes, or press water paddle 5 times in 20 seconds to bypass dispense off.
L0 C BI Control panel locked. Door switch detected as depressed (Door Closed), but control panel keys were pressed, or door was left open more than five (5) minutes. Bypass locked control panel by holding Alarm key, then press either Colder key twice. With control panel unlocked check for defective switch, &/or orange or yellow wire disconnected/defective between control board and door switch. Make repairs if needed. If all check OK, disconnect power to unit, then reconnect.

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Frequently asked

Sub-Zero error code FAQ

What does a flashing SERVICE light on a Sub-Zero mean?

The SERVICE indicator means the control board has logged one or more fault codes. It is a prompt to read the stored codes in diagnostic/service mode — not a single fault by itself. Enter service mode, note the codes, and match them in the reference table to find the affected subsystem.

What is a Sub-Zero 'Clean Condenser' or condenser (EC) alert?

It indicates restricted airflow or a dirty condenser. Vacuum and brush the condenser coils (behind the upper grille on built-in units) and confirm the condenser fan runs. If the alert returns after cleaning, the condenser fan, airflow path or a sealed-system issue should be checked by a technician.

How do I enter Sub-Zero service / diagnostic mode?

On most built-in models you hold a combination of control-panel keys for about five seconds until the display changes, then the panel cycles through stored codes. The exact key sequence varies by model and generation — check your model's manual or call us and we'll walk you through it.

What does code 50 mean on a Sub-Zero?

On 600/700 series controls, code 50 indicates 'excessive refrigerator compressor run' — the refrigerator section is running far longer than expected. Common causes include a dirty condenser, a failing door gasket, a defrost problem or a sealed-system fault.

Can I reset a Sub-Zero error code myself?

Some codes clear after you fix the cause (for example, cleaning the condenser) and reset the control or cycle power. Many codes, however, point to thermistor, defrost, compressor or control-board faults that need diagnosis and parts. If a code returns after a reset, book a technician.

Which models do these codes apply to?

This reference covers Sub-Zero 600/700 series built-in models and modern Built-In (BI) control boards. Wine units, classic, PRO and designer models share much of the same diagnostic logic. If you're unsure which series you have, send us the model number.

Where are the Sub-Zero freezer error codes?

Freezer faults appear in the same table above. Common freezer-related codes include 07 and 08 (freezer thermistors), 10 2 00 and 10 F 00 (freezer thermistor/defrost on BI boards) and 40 2 40 (excessive freezer run time). Search 'freezer', 'defrost' or the code number to filter to them.

What do wine cooler codes like 10E or 15E mean?

Sub-Zero's published code list doesn't define a specific '10E' or '15E' fault, so we won't guess at an exact decode. On wine and beverage units an E-suffixed readout is generally a temperature- or sensor-related alert rather than a documented fault code. The reliable step is to note your exact model and the reading, check the zone setpoint, and if it persists send us the model number so we can diagnose it.

What does EE or 'EE r' mean on a Sub-Zero?

EE is not a numbered code in Sub-Zero's published fault list, so we won't invent a specific decode. An 'EE'-style readout is generally an error or control-communication indicator (often tied to a sensor or a board-communication problem), and a trailing 'r' usually denotes the refrigerator circuit. Read any companion numeric codes in service mode and send us your model number, and we'll confirm exactly what your panel is reporting.

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