Sub-Zero BI built-ins (the Classic built-in line) don’t show a code number on the front panel during normal use. They show a wrench, the service icon, and store a three-part fault code that a technician reads in Fault Code Recall Mode. The control keeps up to 50 codes and drops the oldest when it runs out of room (Sub-Zero Built-In (BI) Series Technical Service Manual, serial #4250000 and later, 7040127, Revision C, May 2015, page 3-38).
The list below is from Sub-Zero’s Built-In (BI) Series Technical Service Manual, serial #4250000 and later (7040127, Revision C, May 2015). Sub-Zero printed two earlier BI manuals, one for units before serial #4100000 (7005333, Revision C, September 2010) and one for serial #4100000 and later (7019014, Revision D, March 2012). Where those say something different, the last column shows it. The manuals list these models: BI-30U, BI-30UA, BI-30UG, BI-36F, BI-36R, BI-36RA, BI-36RG, BI-36S, BI-36U, BI-36UA, BI-36UFD, BI-36UG, BI-42S, BI-42SD and others. For the codes on 600, 700, UC and PRO 48 units, see the Sub-Zero error codes hub.
If the unit smells burned, trips its breaker or is leaking water, stop and book service. Don’t open panels, test wiring or touch the refrigerant circuit.
What the wrench icon tells you
From the BI service manual’s display figures (page 3-34):
| What you see | What the manual says it means |
|---|---|
| Wrench steady, normal temperatures | A minor fault code is logged and not threatening temperatures, or codes weren’t cleared after a technician viewed them |
| Wrench flashing, no chime | A major fault code is logged that threatens temperatures |
| Wrench flashing with a chime | A major fault: immediate action required. Temperature problems, possible appliance damage, or a flood warning (water passing through the flow meter with no call for water) |
| Wrench and ice cube icon flashing | The ice maker water solenoid was energized too long several times, and the ice maker system is disabled until repaired |
The owner steps in Sub-Zero’s Classic Series (BI) Use and Care Guide (9043922 Rev. A, 10/2020) match this. Wrench steady: touch POWER to turn the unit off, check that the condenser area is clean, touch POWER to turn it back on. If the icon is still on, call Sub-Zero Customer Care at 800-222-7820. Wrench flashing, or flashing with a chime: contact service.
How to read a three-part code
Each code has three parts. Take 10 2 02:
- First two digits, the system. 10 thermistor faults, 15 relay faults, 20 defrost heater faults, 30 ice/water/accessory faults, 35 fan faults, 40 runtime faults, 44 glass heater faults, 45 lighting faults, 50 flow meter, 60 load/component faults, 90 control faults, 95 diagnostics, 98 power faults.
- Middle character, the location. 0 misc, 1 refrigerator, 2 freezer, 3 condenser, 4 defrost system, 5 control system, 6 compressors, 7 ambient, 8 icemaker, 9 dispenser, A air purifier, d TC drawer, F freezer evaporator, H high voltage system, L lighting, r refrigerator evaporator, U water systems.
- Last two digits, the failure. For example 00 open, 01 shorted, 02 unstable, 40 excessive run time.
So 10 2 02 is a thermistor fault in the freezer, unstable. The structure is printed on page 3-39 of the manual.
Owner steps while you wait for service
Sub-Zero’s BI manual describes one step aimed at customers: if a major fault needs to be put on hold while waiting for a technician, press and hold ALARM, then POWER, for less than 5 seconds. That suspends the major fault for 24 hours and keeps the full fault history for the technician (Sub-Zero Built-In (BI) Series Technical Service Manual, serial #4250000 and later, 7040127, Revision C, May 2015, page 3-33).
Clearing is different. The manual clears codes only after the problem is fixed, by holding ALARM for 15 seconds, and that erases them. Leave that to the technician.
The use and care guide’s other owner checks: verify power is on and the breaker is on, clean the condenser (power off at the control panel, gloves on, soft brush and vacuum along the fins), and make sure the doors close fully. Replace the air purification cartridge when its icon flashes and the water filter when its icon flashes.
Display messages: LO C, H2 LO and dO Or
The BI manuals for serial #4100000 and later list three messages outside the numbered table (newest manual, page 8-11):
- LO C, control panel locked. The door switch read as pressed (door closed) while someone touched the panel keys, or the door was open more than 5 minutes. The manual’s bypass is to hold the Alarm key, then press either Colder key twice. If it keeps locking, the door switch or its wiring needs a technician.
- H2 LO, dispenser paused. More than 1 gallon was dispensed within 15 minutes, or the water valve was energized 150 seconds. Dispensing stops for 45 minutes. To bypass: on SD models hold the LIGHT key for 5 seconds until 2 chimes; on SID models press the water paddle 5 times in 20 seconds. If it happens again with nobody dispensing, look for a leak and book service.
- dO Or, door left open. The door was open more than 5 minutes with the door alarm turned off. The chime stops when the door closes.
Full BI fault code list
“Steady”, “Flashing” and “Flashing with chime” refer to the wrench icon as listed in the manual. A blank icon cell means the manual lists no icon state for that code. Wording is Sub-Zero’s, including its abbreviations (“evap” is evaporator, “refrig.” is refrigerator).
| Code | What the manual says (s/n 4250000 and later) | Service icon | Older BI manuals |
|---|---|---|---|
| 10 1 00 | Refrigerator Cabinet Thermistor Open. Check ohms and verify temperature readings. | Steady | Same |
| 10 1 01 | Refrigerator Cabinet Thermistor Shorted. Check ohms and verify temp. readings. | Steady | Same |
| 10 1 02 | Refrig. Cabinet Thermistor Unstable. Check for bad connections / damaged wires. | Steady | Same |
| 10 2 00 | Freezer Cabinet Thermistor Open. Check ohms and verify temperature readings. | Steady | Same |
| 10 2 01 | Freezer Cabinet Thermistor Shorted. Check ohms and verify temperature readings. | Steady | Same |
| 10 2 02 | Freezer Cabinet Thermistor Unstable. Check for bad connections / damaged wires. | Steady | Same |
| 10 3 00 | Condenser Thermistor Open. Check ohms and verify temperature readings. | Steady | Inactive (ignore) |
| 10 3 01 | Condenser Thermistor Shorted. Check ohms and verify temperature readings. | Steady | Inactive (ignore) |
| 10 3 02 | Condenser Thermistor Unstable. Check ohms and verify temperature readings. | Steady | Inactive (ignore) |
| 10 3 10 | Inactive (the manual says to ignore it) | Same | |
| 10 3 11 | Inactive (the manual says to ignore it) | Same | |
| 10 3 12 | Inactive (the manual says to ignore it) | Same | |
| 10 7 00 | Ambient Thermistor Open. Check ohms and verify temperature readings. | Ambient Thermistor on Control Board is open. | |
| 10 7 01 | Ambient Thermistor Shorted. Check ohms and verify temperature readings. | Ambient Thermistor on Control Board is shorted. | |
| 10 7 02 | Ambient Thermistor Unstable. Check ohms and verify temperature readings. | Ambient Thermistor on Control Board is unstable. | |
| 10 F 00 | Freezer Evaporator Thermistor Open. Check Ohms and verify temperature Readings. | Steady | Same |
| 10 F 01 | Freezer Evaporator Thermistor Shorted. Check Ohms and verify temp. Readings. | Steady | Same |
| 10 F 02 | Freezer Evaporator Thermistor Unstable. Check for bad connections / damaged wires. | Steady | Same |
| 10 r 00 | Refrigerator Evaporator Thermistor Open. Check Ohms and verify temp. Readings. | Steady | Same |
| 10 r 01 | Refrigerator Evaporator Thermistor Shorted Check Ohms and verify temp. Readings. | Steady | Same |
| 10 r 02 | Refrig. Evaporator Thermistor Unstable. Check for bad connections / damaged wires. | Steady | Same |
| 10 r 09 | 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. | Same | |
| 15 1 00 | Refrigerator Compressor Relay stuck open. No power to Compressor. Verify, replace control board. | Flashing with chime | Same |
| 15 1 01 | Refrigerator Compressor Relay is stuck closed. Power to compressor at all times. Verify, replace control board. | Flashing with chime | Same |
| 15 2 00 | Freezer Compressor Relay stuck open. No power to Compressor. Verify, replace control board. | Flashing with chime | Same |
| 15 2 01 | Freezer Compressor Relay is stuck closed. Power to compressor at all times. Verify, replace control board. | Flashing with chime | Same |
| 15 4 00 | Defrost Relay is stuck open. No power to defrost heater. Verify, replace control board. | Steady | Same |
| 15 4 01 | Defrost Relay stuck closed. Power to defrost heater at all times. Verify, replace control board. | Flashing | Same |
| 15 8 00 | Icemaker Relay is stuck open. No power to icemaker. Verify, replace control board. | Same | |
| 15 8 01 | Ice Maker Relay stuck closed. Power to icemaker at all times. Verify, replace control board. | Same | |
| 15 8 10 | Ice Accessories Relay is stuck open. No power to ice accessories (fill tube heater, mullion heater). Verify, replace control board. | Same | |
| 15 8 11 | Ice Accessories Relay is stuck closed. Power to ice accessories (fill tube heater, mullion heater) at all times. Verify, replace control board. | Same | |
| 15 9 00 | Dispenser Auger Relay stuck open. No power to auger. Verify, replace control board. | Auger Relay is stuck open. No power to auger. Verify, replace control board. | |
| 15 9 01 | Auger Relay is stuck closed. Power to auger at all times. Verify, replace control board. | Steady | Same |
| 15 9 65 | Water Valve Selecting Relay stuck at Dispenser water position. Ice making system disabled. Replace control board. | Same | |
| 15 9 66 | Water Valve Selecting Relay stuck at Icemaker water position. Replace control board. | Same | |
| 15 L 00 | Main Lights Relay stuck open. Power to lights at all times. Verify, replace control board. | Same | |
| 15 L 01 | Main Lights Relay is stuck closed. No voltage to lights. Verify, replace control board. | Same | |
| 15 L 55 | Inactive (the manual says to ignore it) | Accent lights triac open. Verify no power to accent lights. Verify, replace control board. | |
| 15 L 56 | Inactive (the manual says to ignore it) | Accent lights triac shorted. Verify constant power to accent lights regardless of activation. Verify, replace control board. | |
| 15 U 00 | Water Valve Relay is stuck open. No power to water valve. Verify, replace control board. | Same | |
| 15 U 01 | Water Valve Relay is stuck closed. Power to water valve at all times. Verify, replace control board. | Flashing with chime | Same |
| 15 U 10 | Water Check Valve Relay is stuck open. No power to check valve. Verify, replace control board. | Not listed | |
| 15 U 10 | Water Check Valve Relay is stuck closed. Power to water valve at all times. Verify, replace control board. (this code is printed twice in the manual) | Not listed | |
| 20 2 00 | Defrost Bi-metal stuck open. Verify the bi-metal is open circuit below 40°F (4°C). Replace if necessary. | Steady | Same |
| 20 2 01 | Defrost Bi-metal stuck closed. Verify the bi-metal is closed above 70°F (21°C). Replace if necessary. | Steady | Same |
| 20 2 05 | Mis-wired Bi-metal. Normal temps during defrost, but inappropriate response from bimetal. Check wiring and bi-metal mounting. | Same | |
| 20 2 06 | Mis-wired Bi-metal. High temps during defrost, and inappropriate response from bimetal. Check wiring and bi-metal mounting. | Steady | Same |
| 20 2 07 | Defrost Bi-metal Error - Check Bi-metal ohms. Replace heater if necessary. | Defrost Heater Error - Check heater ohms. Replace heater if necessary. | |
| 20 2 50 | Defrost Heater Open. Verify wiring and heater. Check heater ohms. Replace heater if necessary. | Steady | Same |
| 30 8 00 | Ice accessories open circuit. Check wiring for fill tube heater (and mullion chute heater, if equipped). | Same | |
| 30 8 05 | No signal from icemaker for fill. Check wiring and power to ice maker. | Same | |
| 30 8 10 | Icemaker open circuit. Check power and wiring to icemaker. | Same | |
| 30 8 30 | Water valve not opened but water observed passing through. | Flashing with chime | Same |
| 30 9 01 | Bulk Ice Switch stuck closed. Bulk ice switch pressed/closed for >5 seconds with door closed. | Bulk ice / Internal dispenser ice switch stuck closed, pressed > 5 sec. with door closed | |
| 30 9 10 | Dispenser auger open. Check wiring and power to auger motor. Check auger ohms. | Same | |
| 30 9 80 | Check communications cable to dispenser. | Same | |
| 30 9 86 | 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. | Same | |
| 30 U 00 | Water valve open. Check wiring and power to water valve. Check solenoid ohms. | Same | |
| 30 U 10 | Dispenser water valve open. Check wiring and power to water valve. Check solenoid ohms. | Same | |
| 30 U 20 | Water Check Valve open circuit. Solenoid is open. | Not listed | |
| 35 3 00 | Inactive (the manual says to ignore it) | Condenser fan open. Check wiring and power to condenser fan. Check fan ohms. | |
| 35 3 35 | Inactive (the manual says to ignore it) | Same | |
| 35 A 36 | Check air filter fan is connected properly and functioning. | Same | |
| 35 A 37 | Check air filter fan is connected and no shorts are evident. | Same | |
| 35 F 33 | Check Freezer evap. fan for obstructions that cause inability to achieve full speed. | Verify Freezer evaporator fan not shorted - the fan is running faster than its setting. | |
| 35 F 34 | Verify Freezer evaporator fan not shorted - the fan is running faster than its setting. | Check Freezer evap. fan for obstructions that cause inability to achieve full speed. | |
| 35 r 33 | Check Refrigerator evap. fan for obstructions that cause inability to achieve full speed. | Verify Refrig. evaporator fan not shorted - the fan is running faster than its setting. | |
| 35 r 34 | Verify Refrig. evaporator fan not shorted - the fan is running slower than its setting. | Check Refrigerator evap. fan for obstructions that cause inability to achieve full speed. | |
| 40 1 38 | Refrigerator stepper valve communication fault. Replace control board. | Not listed | |
| 40 1 40 | Excessive Refrigerator run time. Verify performance of unit and check for door leaks, door ajar, proper charge in system, and icing of evap. | Steady | Same |
| 40 2 38 | Freezer stepper valve communication fault. Replace control board. | Not listed | |
| 40 2 40 | Excessive Freezer run time. Verify performance of unit and check for door leaks, door ajar, proper charge in system, and icing of evap. | Steady | Same |
| 40 8 40 | Icemaker ran for maximum fill time without achieving necessary volume. Check for water system blockages, kinked water lines, proper water pressure to unit. | Same | |
| 40 9 40 | Dispenser active for maximum fill time. Water was dispensed for 150 seconds. Verify no stuck keys or flooding. | Same | |
| 40 b 38 | Baffle stepper communication fault. Replace control board. | Not listed | |
| 44 0 00 | Glass door heater open circuit. Check wiring and power to heater. Check heater ohms. | Same | |
| 44 0 01 | Glass door heater short circuit. Check wiring and power to heater. Check heater ohms. | Same | |
| 44 9 42 | 1 watt glasswell heater not detected. Check wiring and power to heater. Check heater ohms. | Same | |
| 44 9 43 | 4 watt glasswell heater not detected. Check wiring and power to heater. Check heater ohms. | Same | |
| 45 1 00 | Main Refrigerator lights open circuit. Check lights and wiring. | Same | |
| 45 2 00 | Main Freezer lights open circuit. Check lights and wiring. | Same | |
| 45 1 01 | Main Refrigerator lights short circuit. Check lights and wiring. | Same | |
| 45 2 01 | Main Refrigerator lights short circuit. Check lights and wiring. | Same | |
| 45 A 45 | Air filter light burned out. Replace air filter cartridge. | Air filter icon flashing | Same |
| 45 L 00 | Accent lights open circuit. Check lights and wiring. | Same | |
| 45 L 01 | Accent lights short circuit. Check lights and wiring. | Same | |
| 50 U 80 | Water Flow meter not detected. Verify power and wiring to flow meter assembly. If power and wiring are OK, replace flow meter assembly. | Same | |
| 50 U 86 | Water Flow meter detected low flow. Verify water pressure and check for any water system obstructions. | Same | |
| 50 U 87 | Water Flow meter did not detect flow. Verify water pressure, water flow, and that meter is not blocked or dirty. | Same | |
| 60 1 02 | Refrigerator variable speed compressor communication error. Replace control board. | Not listed | |
| 60 1 38 | Refrigerator variable speed compressor communication error. Replace control board. | Not listed | |
| 60 1 60 | No Refrigerator compressor load detected. Check compressor electricals and wiring. | Steady | Same |
| 60 2 02 | Freezer variable speed compressor communication error. Replace control board. | Not listed | |
| 60 2 38 | Freezer variable speed compressor communication error. Replace control board. | Not listed | |
| 60 2 60 | No Freezer compressor load detected. Check compressor electricals and wiring. | Steady | Same |
| 90 0 70 | Flash Failure. Reconfigure control board. Replace control board if reconfigure fails. | Same | |
| 90 0 71 | Flash Failure. Reconfigure control board. Replace control board if reconfigure fails. | Same | |
| 90 0 72 | Flash Failure. Reconfigure control board. Replace control board if reconfigure fails. | Same | |
| 90 0 73 | Flash Failure. Reconfigure control board. Replace control board if reconfigure fails. | Same | |
| 90 0 74 | Flash Failure. Reconfigure control board. Replace control board if reconfigure fails. | Same | |
| 90 0 75 | Flash Failure. Reconfigure control board. Replace control board if reconfigure fails. | Same | |
| 90 0 81 | Microcontroller fault. Replace control board if fault is active. | Same | |
| 90 0 90 | Microcontroller fault. Replace control board if fault is active. | Same | |
| 90 0 92 | Microcontroller fault. Replace control board if fault is active. | Same | |
| 90 0 93 | Microcontroller fault. Replace control board if fault is active. | Same | |
| 90 3 38 | Inactive (the manual says to ignore it) | Condenser fan triac is faulted. Verify condenser fan operation. Replace control board if fault is active. | |
| 90 3 55 | Condenser fan triac Open. Verify condenser fan operation. Replace control board if fault is active. | Same | |
| 90 3 56 | Condenser fan triac shorted. Verify condenser fan operation. Replace control board if fault is active. | Same | |
| 90 5 01 | Key shorted or damaged on Control Panel. Verify key performance. Replace Control Panel. | Same | |
| 90 5 38 | 12V Fan power output fault. Verify constant 12V DC to evaporator fan. Replace control board if fault is active. | Steady | 12V Fan power output fault. Verify constant 12V DC to evaporator and drawer fans. Replace control board if fault is active. |
| 90 5 39 | Inactive (the manual says to ignore it) | DC Fan output faults. Verify proper evaporator and drawer fan operation | |
| 90 5 44 | Glass door heater output fault. Check wiring and power to heater. Replace control board if fault is active. | Same | |
| 90 5 80 | No keypad communications. Check wiring and key performance of Control Panel. | Same | |
| 90 5 85 | User display failure. Replace Control Panel. | Same | |
| 90 5 95 | Key shorted or damaged on Control Panel. Verify key performance. Replace Control Panel. | Same | |
| 90 5 96 | Key shorted or damaged on Control Panel. Verify key performance. Replace Control Panel. | Same | |
| 90 5 97 | Control Panel microcontroller problem. Verify key performance. Replace Control Panel. | Same | |
| 90 5 99 | Control Panel error. Verify key performance. Replace Control Panel. | Same | |
| 90 9 80 | No communications with door dispenser. Check proper model configuration. Check wiring to dispenser. | Same | |
| 90 A 38 | Air filter fan output fault on control board. Replace control board if fault is active. | Same | |
| 90 A 56 | Inactive (the manual says to ignore it) | Not listed | |
| 90 b 80 | No stepper micro communication. Replace control board | Not listed | |
| 90 F 38 | Freezer evap fan output fault on control board. Verify if fan is working. Replace control board if fault is active. | Steady | Same |
| 90 H 80 | Communications problems on main board. Replace control board. | Steady | Same |
| 90 H 82 | Intermittent communications on main board. Replace control board. | Same | |
| 90 H 83 | Communications problems on main board. Replace control board. | Same | |
| 90 H 84 | Initialization fault. Power unit OFF, then ON, and verify if code remains active. Replace control board if fault is active. | Same | |
| 90 L 38 | Check if accent lights are working. Replace control board if fault is active. | Same | |
| 90 r 38 | Refrigerator evaporator fan output faulted. Verify fan operation. Replace control board if fault is active. | Steady | Same |
| 95 1 25 | Verify Refrigerator evaporator is cooling properly when compressor is on. Check sealed system charge if not. | Same | |
| 95 2 25 | Verify Freezer evaporator is cooling properly when compressor is on. Check sealed system charge if not. | Same | |
| 95 1 00 | Refrig. compressor microprocessor pin stuck in off position. Replace control board. | Not listed | |
| 95 1 01 | Refrig. compressor microprocessor pin stuck in on position. Replace control board. | Not listed | |
| 95 2 00 | Freezer compressor microprocessor pin stuck in off position. Replace control board. | Not listed | |
| 95 2 01 | Freezer compressor microprocessor pin stuck in on position. Replace control board. | Not listed | |
| 98 0 98 | Brownout conditions were detected. | Same | |
| 10 d 00 | Not listed in this manual | Inactive (ignore) (both older BI manuals) | |
| 10 d 01 | Not listed in this manual | Inactive (ignore) (both older BI manuals) | |
| 10 d 02 | Not listed in this manual | Inactive (ignore) (both older BI manuals) | |
| 30 9 02 | Not listed in this manual | Water switch stuck closed, pressed > 5 seconds with door closed. (s/n 4100000 manual only) | |
| 35 d 35 | Not listed in this manual | Inactive (ignore) (both older BI manuals) | |
| 35 d 36 | Not listed in this manual | Drawer Fan current is too low. Verify wiring & check for open circuits or damaged fans. (both older BI manuals) | |
| 35 d 37 | Not listed in this manual | Drawer Fan current is too high. Verify wiring and check for stalled fan or shorts. (both older BI manuals) | |
| 90 d 38 | Not listed in this manual | Drawer fan output fault on control board. Replace control board if fault is active. (both older BI manuals) | |
| 90 d 80 | Not listed in this manual | Inactive (ignore) (both older BI manuals) |
What to send when you book
Photograph the panel, note whether the wrench is steady, flashing or chiming, and save the model and serial number from the rating plate. Don’t clear the code.
We’re an independent Sub-Zero specialist, not an authorized service center. If your BI is still under Sub-Zero’s warranty, call Sub-Zero first. Out of warranty, the $99 diagnostic is credited toward the repair, and you get a written estimate before any work starts. Book through our contact page or read more on our Sub-Zero repair page.