Sub-Zero · Error codes
Sub-Zero 600 and 700 Series Diagnostics
What a 600 or 700 series Sub-Zero can tell you depends on when it was built. The earliest controls show words or a dash pattern, later ones keep numbered codes from 05 to 50, and some 700 freezers add a block in the 80s for their variable speed compressor.
$79 service call, applied to the repair. Monday to Saturday, 8 AM to 7 PM.
In short: read the serial number first, because the same display means different things from one era to the next. A flashing SERVICE usually means a compressor ran far too long; a steady one means codes are stored. The numbers show only in a technician's diagnostic mode, and most point at a sensor, the freezer defrost, the ice maker fill or long runs. Meanings vary by model and production era.
Which control your 600 or 700 has
Codes depend on the control, and the serial number tells us which one your unit was built with. The serial tag is inside the unit; its place varies by model, so photos of the upper inside walls and the grille area help.
| Line and era | Serial numbers | What the display shows | Numbered codes |
|---|---|---|---|
| 600, original | Before serial 1810000 | VACUUM CONDENSER, SERVICE, EE and ICE | None; faults are spelled out |
| 600, mid-run | Serial 1810000 to 2149537 | SERVICE flashing or steady, ICE, door alarm bell | Yes, plus a temperature history |
| 600-2 and 600-3 | About serial 2150000 on; the -3 from serial 2600000 | The same, on UNIT ON/OFF, ALARM, ICE, WARMER and COLDER keys | 05 to 08, 20 to 24, 30, 40, 50 |
| 700, original | Before serial 1670316 | Double dashes when off; -20- or -55- with a flashing zone indicator | None |
| 700-2 tall | Serial 1670316 to 2347395 | SERVICE, ICE, door alarm | 05 to 08 and 20 to 24 on later units; 80 to 88 on the 700TF/I-2V; no 30, 40 or 50 |
| 700-3 base drawers | The -3 run of the 700BR, 700BF/I and 700BC/I | POWER, ALARM, ICE MAKER, WARMER, COLDER keys | 05, 07, 08, 20 to 24, 30, 40, 50 |
| 700-3 tall and 736 | After serial 2377228; revised 736 after serial 2970000 | SERVICE, ICE, door alarm, Sabbath and showroom | 05 to 08, 20 to 24, 30, 40, 50; the 700TF/I-3 adds compressor controller codes |
The 700-2 tall units gained codes partway through the run: the 700TC/I-2 after serial 1759493, the 700TR-2 after serial 1759163, and the 700TF/I-2 and -2V after serial 1757258. Earlier units and the 700-2 base drawers have simpler controls. A board replaced on a past call may log codes the serial says it should not, so we check the board, not just the tag. Background on each line is on 600 series repair and 700 series repair.
What you can read on the display yourself
None of these needs a service mode.
- VACUUM CONDENSER flashing (original 600): clean the coil behind the top grille with the breaker off; see the condenser cleaning guide. It can appear while temperatures still look fine.
- EE in place of a temperature (original 600): that section's sensor reads out of range, usually with SERVICE flashing.
- -20- or -55- with a flashing zone indicator (original 700): the sensor in that zone is unplugged or failed open (-20-) or shorted (-55-). The error stays until the sensor is fixed and the unit is powered down and up.
- Double dashes for temperatures (original 700): the unit is off at the keypad; COLDER starts it again.
- SERVICE flashing (later controls): a temperature problem, usually a compressor running far past its normal cycle.
- SERVICE steady: codes are stored, often left after a technician viewed them. Not urgent with normal temperatures.
- ICE missing: the ice maker is switched off at the keypad. ICE and SERVICE flashing together: the control saw a problem in the ice system, most often the water fill.
- Lights on, nothing cooling: on a 600 from serial 1810000 on, or a 700-2 and later, this can be showroom mode, which keeps the lights and display on with cooling off. The owner's guide shows how to tell. If it is not showroom mode, call.
For alarms, see Sub-Zero alarm beeping; the service light page compares how the light behaves across the series.
How a technician reads the stored codes
On coded 600 and 700 controls, the numbers show only in diagnostic mode, marked EC, ahead of the temperatures. SERVICE then stays on steady until the codes are cleared by hand after the repair. From the mid-run 600 and the 700-2 on, the control also keeps a temperature log with event markers, which shows whether a section warmed slowly over days (frost, defrost) or jumped once (a door, a power cut).
We do not publish the key sequences: the same panel leads into modes that switch parts on by hand, disable a zone or change the model setup.
The code list, grouped by system
The codes documented for the 600-2, 600-3, 700-2, 700-3 and 736, in plain words. Refrigerator-only units have no freezer sensors, the 700-3 base drawers do not use 06, and the 700-2 logs only the sensor and defrost codes, plus 80 to 88 on the 700TF/I-2V.
Temperature sensors: 05 to 08
| Code | What it means | What to do |
|---|---|---|
| 05 | Refrigerator compartment sensor read open, shorted or jumpy long enough for the control to stop trusting it | Check the section with a thermometer and book a visit. |
| 06 | Refrigerator evaporator sensor, which tells the control when the coil is clear of frost | Look for frost on the refrigerator back wall; book a visit. |
| 07 | Freezer compartment sensor read open, shorted or erratic | Watch the freezer temperature, protect the food, call. |
| 08 | Freezer evaporator sensor, so defrost cannot end on temperature | Expect frost buildup. Call before ice blocks the coil. |
Freezer defrost: 20 to 24
| Code | What it means | What to do |
|---|---|---|
| 20 | The defrost heater circuit looks broken and the freezer coil did not warm | Usually a burned-out heater, the heater's safety thermostat (the defrost terminator) or a loose connection. Call. |
| 21 | Defrost ran too hot | Often a sensor reading wrong or out of place. Call. |
| 22 | The control could not confirm the defrost heater circuit is complete | A break somewhere in the heater circuit; frost builds over several days. |
| 23 | The defrost ran too hot, and the heater circuit also looked broken | Two faults together, often wiring or the heater's safety thermostat. |
| 24 | Defrost ran its full time without warming the coil enough | A weak heater, a coil packed with ice from a door left open, or a frozen drain. |
Ice maker fill and long compressor runs: 30, 40, 50
Not on the 700-2, where a long compressor run shows only as a flashing SERVICE.
| Code | What it means | What to do |
|---|---|---|
| 30 | The ice maker water valve stayed powered longer than allowed; on the 600-2 and 600-3 it takes several long fills | Look for fused ice or water in the bucket. Close the supply valve if water reaches the floor. |
| 40 | The freezer compressor ran far longer than a normal cycle | Clean the condenser with the breaker off and check that every freezer door and drawer closes on its own. |
| 50 | The refrigerator compressor ran far too long; on 700BR-3 drawers it tracks the refrigerator fan | The same checks on the refrigerator side. A 700 breathes through the toe-kick, not a top grille. |
Variable speed freezer compressor: 80 to 88
The 700TF/I-2V all-freezer has a variable speed compressor with its own controller, and these codes come from that pair; the 700TF/I-3 logs a similar group. Do not keep cycling the power to clear them.
| Code | What it means | What to do |
|---|---|---|
| 80 to 83 | The compressor is struggling: it is working too hard, getting low voltage, drawing too much current, or will not start | Clear the toe-kick grille and call. We test the compressor and its power supply before quoting. |
| 84 and 85 | The compressor's own controller shut it down, for a short circuit or for overheating | For 84, switch the breaker off and leave it off. For either, call. |
| 86 to 88 | The main board and the compressor controller are not talking to each other | Most often a connection or one of the two boards, not the compressor itself. Call. |
What the codes usually turn out to be
A code names a circuit or a condition, not a part.
Long-run codes 40 and 50 with SERVICE flashing
What it usually is: a matted condenser, then a door that no longer seals, a frosted coil or a slow fan. A low charge or a tired compressor comes well below those. On a 700 the coil is at floor level, where pet hair and rug edges block it.
What you can check: the coil with the breaker off, each door closing by itself from halfway, and frost on the warm section's back panel.
What we do: clean the coil, test the fans, read the log, and take pressure readings if it still lags. A compressor job looks like our failed freezer compressor repair; see also running constantly.
Defrost codes 20 to 24
What it usually is: a burned-out heater, a heater safety thermostat that no longer closes, or a freezer evaporator sensor reading wrong. On a 700 a frozen drain trough often comes with it, and melt water then spills under the bottom drawer.
What you can check: whether frost covers the freezer back panel or only its lower edge, and whether melt water reaches the kickplate after each defrost. Do not chip at the ice.
What we do: test the circuit, replace the failed part, thaw the coil, clear the drain and confirm a defrost. See frost buildup.
Sensor codes, EE, -20- and -55-
What it usually is: the sensor, then its plug or a damaged lead, and on older units a corroded splice. A failed board input is uncommon.
What you can check: a refrigerator thermometer on a middle shelf overnight, compared with the display.
What we do: measure the sensor at the board against a known temperature, replace the sensor or repair the wiring, and confirm the code stays clear.
Code 30 and ICE problems
What it usually is: an ice maker that stalls mid-cycle and holds the valve open, a sticking valve, or a frozen fill tube. Two things look like faults and are not: the control rests the ice maker about 45 minutes after each harvest, and on many 600-3 and 700-3 models a switch stops production when the bucket is not fully seated.
What you can check: whether ICE is lit at all, whether the bucket is fully seated, and whether ice has formed around the fill tube at the back of the ice maker. A code 30 with water in the bucket points at the fill. See ice maker not working.
What we do: cycle the ice maker and test the valve and fill tube heater. The 600-3 and 700TC/I-3 used two ice maker makes and the 700TF/I-3 a third, so we check which one is in your freezer before ordering.
Stay safe. Do not count on the keypad to cut power; use the breaker before you lift a grille or vacuum a kickplate. Do not pull a built-in from its opening; it can tip forward. Never add refrigerant. If an 80s code comes with a burning smell, switch the breaker off and leave it off.
What the repair behind a code costs
The service call is $79. It covers the trip and the diagnosis, including reading the codes and the log, and is applied to the repair once you approve the written price.
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.
Original-era boards and some 700 parts are scarcer, and we give you the lead time first. See pricing and built-in refrigerator 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 600 and 700 diagnostics: questions
Does my Sub-Zero 600 series store error codes?
Only if it was built from serial 1810000 on, or its board was replaced with a later one. Earlier units spell faults out as VACUUM CONDENSER, SERVICE or EE.
What do codes 40 and 50 mean on a Sub-Zero 650 or 695?
On a 650 or 695 each section has its own compressor, so 40 points at the freezer system and 50 at the refrigerator system. Start with the coil behind the top grille, cleaned with the breaker off, and the door on that side. We suspect the compressor last, after measurements.
What do -20- and -55- mean on my Sub-Zero 700TR?
On an original 700, built before serial 1670316, -20- means that zone's sensor is open or unplugged and -55- means it is shorted. The sensor or its wiring needs repair.
My 700TF/I shows a code in the 80s. Is the compressor dead?
Not necessarily. The controller, the wiring or the main board can set those codes as easily as the compressor, so we test the controller and the compressor windings before quoting. Sealed-system work is in-house; see sealed-system repair and compressor replacement.
Why did the codes come back after another technician cleared them?
Clearing erases the record, not the cause. If the fault was never fixed, the control logs it again.
Will a new control board fix the code?
Rarely, since most codes point at a sensor, a defrost part or long runs. When a board does fail, the new one must be set up for your exact model, which we do on site.