Sub-Zero 700-2 Code 81: Variable-Speed compressor fails to start

What 81 means

On the 700 Series 700-2 with a variable-speed compressor, the 700TCI being one example, code 81 means the VS compressor will not start. The documented correction is to replace the VS compressor controller, the electronic module that drives the compressor. With the compressor stuck at rest, cooling stops, and both temperature readings climb over the following hours while lights and display keep working.

Common causes of 81

VS compressor controller no longer starting the compressor
Connection between controller and compressor worth checking during the visit

✓ One safe check you can try

1. Note code 81. 2. Reset power at the breaker for two minutes and listen for the compressor. 3. Keep all doors closed. 4. Move perishables to a cooler if temperatures pass 40°F in the fresh-food side. 5. Call us for a visit.

! Why to stop there

The controller sits beside line voltage in the machine compartment.
Controller replacement must match your exact 700-2 model.
Wiring has to be reconnected correctly or the code returns.

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.

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Other Refrigerator codes

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8181 questions

What does code 81 mean on my 700TCI?

It means the variable-speed compressor will not start. On the 700-2 the documented fix is a new VS compressor controller, which is the electronic drive for the compressor rather than the compressor itself.

Is the compressor ruined?

Code 81 points to the controller, not the compressor. Replacing the controller usually brings cooling back, and we confirm the reading on site before ordering anything.

What will it cost?

We confirm the reading and give you a written price for the controller and labor before work begins. Our workmanship is covered for 30 days.