Sub-Zero Classic BI Code 10/R/01: Refrigerator evaporator sensor shorted

What 10/R/01 means

On legacy Sub-Zero Classic built-in units such as the BI-36U/S and BI-36UFD/S, 10/R/01 means the refrigerator evaporator thermistor is reading as shorted. That sensor reports how cold the fresh-food coil is, and the control relies on it to time defrost and fan operation. With a shorted reading the board cannot trust the coil temperature at all. You see the code on the display, and the refrigerator side may frost over or slowly drift warmer. The same code is sometimes written with dashes as 10-R-01.

Common causes of 10/R/01

Shorted refrigerator evaporator thermistor
Pinched or chafed sensor wiring between the coil and the control
Corroded or damp connection where the sensor harness plugs in

✓ One safe check you can try

1) Write down the exact code shown before anything else. 2) Keep the refrigerator door closed so the food stays cold while you wait for a technician. 3) Look at the temperature readout; if it climbs above 40°F, move perishables to a cooler. 4) Turn the unit off and back on at the breaker once to see whether the code returns. 5) Do not chip ice off the coil cover.

! Why to stop there

The sensor sits behind the evaporator cover, inside the cooled cabinet.
A shorted reading has to be confirmed with resistance tests at the right temperature.
Replacing the probe means routing new wire without damaging the cabinet liner.

Opening a panel yourself does not automatically cancel a manufacturer warranty, but it can cause accidental damage, and some manufacturers set their own service conditions. Check your warranty terms, or ask us, before deciding.

→Same appliance

Other Refrigerator codes

ddSub-Zero 600 and 700 Series Display dd: Diagnostics switched off deSub-Zero 600 and 700 Series Display de: Diagnostics enabled 23Sub-Zero 600, 700 and 648PRO Code 23: Defrost overheat with no feedback 50Sub-Zero 600 and 700 Series Code 50: Refrigerator compressor running too long 41Sub-Zero 648PRO Code 41: Zone compressor or wiring problem 81Sub-Zero 700-2 Code 81: Variable-Speed compressor fails to start 82Sub-Zero 700-2 Code 82: VS compressor controller needs replacement 88Sub-Zero 700TF Code 88: Board and compressor controller not talking

10/R/0110/R/01 questions

Can I keep using the refrigerator with 10/R/01 showing?

Usually for a short time, yes. The compressor may still run, but defrost timing is no longer reliable, so the coil can ice up. Keep the door closed, watch the temperature, and book a visit before the food side starts warming.

Is 10/R/01 different from 10-R-01?

No. They are the same Classic BI code written two ways. Both point to a shorted refrigerator evaporator thermistor, and the repair path is identical.

What does the repair usually involve?

We confirm the reading at the sensor and at the control, then replace the thermistor or repair its wiring. You get a written price before we start, and the work carries our 30-day workmanship warranty.