Sub-Zero Classic BI Code 15/1/01: Compressor relay stuck closed

What 15/1/01 means

On older Sub-Zero Classic BI models like the BI-36U/S, and on current Designer units such as the DET3050CI and DEC3050R, 15/1/01 reports a compressor relay stuck closed. On the Classic BI it is the refrigerator compressor relay, and the control believes power is reaching the compressor all the time; electrical noise on the line can trigger it. On Designer models the same number refers to the zone 1 compressor relay. Owners may notice nonstop running or an overly cold section. A later Classic software update stopped this code from appearing on the display.

Common causes of 15/1/01

Electrical noise or interference on the supply line fooling the relay sense circuit
Outdated control software on Classic BI units
Relay contacts welded shut on the control board

✓ One safe check you can try

1) Note whether the compressor seems to run without stopping. 2) Check the temperature settings and the actual readout in each section. 3) Make sure nothing heavy on the same circuit, such as a space heater, is plugged in near the unit. 4) Power the unit off at the breaker for a minute and restore it. 5) If the code comes back, call us.

! Why to stop there

Checking for welded relay contacts requires testing the board under live voltage.
The software update needs a dealer diagnostic tool and the correct file.
A compressor that never stops can overheat, so guessing wastes time you may not have.

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

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 80Sub-Zero 700TF Code 80: No inverter feedback after a board change ddSub-Zero 600 and 700 Series Display dd: Diagnostics switched off

15/1/0115/1/01 questions

Why would my compressor run all the time with 15/1/01?

The relay that switches the compressor is reported as closed, so power may never be cut. On many Classic BI units the cause is line interference rather than a broken relay, which is why the software update matters.

Does 15/1/01 mean the same thing on a Designer column?

Close to it. On Designer units it is the zone 1 compressor relay stuck closed. We check the zone 1 relay circuit and control rather than the Classic refrigerator relay.

Will a software update fix it?

On Classic BI units it often stops the display from showing the code. If the relay is truly welded, the board still needs work. We quote the job in writing before we begin.