Wolf M Series Code 3221: Upper RTD open

What 3221 means

On Wolf M Series wall ovens, 3221 reports that the upper oven's RTD temperature sensor is read as open, with 3222 for the lower oven. The same code is documented for the E Series. The control sees no signal from the sensor, so the upper oven may not preheat and the display shows the code. The control protects itself by refusing to heat without a trusted reading.

Common causes of 3221

The upper RTD sensor has opened internally
A loose or broken RTD connector or wire
The relay board RTD input

✓ One safe check you can try

1. Cancel cooking and allow the cavity to cool. 2. Unplug any temperature probe from the oven and try again. 3. Reset power at the breaker for about a minute. 4. A repeat code needs a technician with a meter.

! Why to stop there

The sensor and the board input produce the same code, so replacing one blindly may not help.
On this code the cause may also be a loose or broken RTD connector or wire, or the relay board RTD input, so we rule each out before we quote.

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 Wall Oven codes

0121Wolf M Series Oven Code 0121: upper right convection relay shorted 0221Wolf M Series Code 0221: Upper Bake Element DLB Shorted 0321Wolf M Series Oven Code 0321: Broil Relay Shorted on the Upper Element 0421Wolf M Series Code 0421: upper left convection relay shorted 0630Wolf M Series Oven Code 0630: Auxiliary DLB Shorted 2420Wolf M Series Code 2420: Relay board RTD circuit 3D20Wolf M Series Code 3D20: Input voltage frequency error 2631Wolf M Series Code 2631: Relay board door switch circuit

32213221 questions

What is the difference between 3121 and 3221?

Both name the upper RTD, the oven's temperature sensor. Code 3121 reads it shorted and 3221 reads it open. The result is the same, with no usable temperature, and the repair is usually the sensor or its wiring.

Will food burn if I keep cooking?

It might. The control may misjudge heat or shut off without warning. Use a separate oven thermometer if you must cook, and keep it brief. We recommend booking the sensor check first.

What does the visit include?

The technician reads the logged code, measures the sensor circuit, finds whether the part or the board has failed, and writes the price down for your approval. Our 30-day workmanship warranty applies.