Sub-Zero Designer Code 35-1-00: Zone 1 fan circuit open

What 35-1-00 means

On Sub-Zero Designer units like the DET3050CI and DEC3050R, 35-1-00 reports Zone 1 as open within the fan code family. In practice the board sees an open circuit on the Zone 1 evaporator fan, the fan that pushes cold air through that compartment. Without airflow, the coil may frost while the zone warms. You may hear silence where a soft fan hum used to be, and the Zone 1 temperature can climb slowly.

Common causes of 35-1-00

A disconnected plug at the Zone 1 evaporator fan
A broken wire in the fan harness
A Zone 1 fan motor with an open winding
A board output that does not reach the fan

✓ One safe check you can try

1. Open the door and listen for the fan; note whether it runs when the door switch is pressed. 2. Check that food is not pressed against the rear vents. 3. Reset the breaker once. 4. Put a thermometer in Zone 1 and move food if it rises above 40 degrees.

! Why to stop there

The fan is mounted behind the evaporator cover
Frost may need careful melting before access
Testing the fan circuit requires live readings

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

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 deSub-Zero 600 and 700 Series Display de: Diagnostics enabled

35-1-0035-1-00 questions

How do I know the Zone 1 fan stopped?

With the door open and the switch pressed, many Designer units run the fan. If you hear nothing and 35-1-00 is showing, the fan circuit is likely open. We confirm with a meter.

Can frost block the fan and cause this code?

Ice can stop a fan, but 35-1-00 specifically reports an open circuit. We melt any frost, check the plug, wire and motor, and repair what is open.

How quickly should I call?

Fairly soon. Without airflow, Zone 1 warms over hours to a day. Keep the door closed and check the temperature. We give a written price before work.