Dacor Oven Error Code U31

U31 means the upper or single oven temperature sensor probe 1 has been detected as shorted. The relay board's analog-to-digital converter registered a value of 0x0010 or lower for 60 consecutive seconds, indicating the sensor circuit resistance has collapsed far below normal operating range. This typically points to a failed probe, a damaged wiring harness, or a loose connector at the relay board.

No, it is not safe to operate the oven while U31 is active. The temperature sensor provides the control board with the data it needs to regulate oven heat. A shorted sensor means the board cannot accurately read cavity temperature, which removes the primary safeguard against overheating. The oven should remain off until the probe, connector, or harness is inspected and repaired.

Start by checking the probe connector at the relay board for a secure fit and signs of corrosion or damaged pins. Next, disconnect the temperature probe and use a multimeter to measure resistance across the probe terminals. A reading near zero ohms confirms an internally shorted probe that needs replacement. If the probe resistance reads correctly, trace the wiring harness from the probe to the relay board and look for any areas where insulation is melted, pinched, or chafed.

A power reset may temporarily clear the U31 code, but if the underlying short condition still exists in the probe or harness, the fault will return within 60 seconds of the oven attempting to read temperature again. The oven cannot accurately regulate heat without a functioning temperature sensor, so continued use without repair is not recommended and could result in uncontrolled heating.

If only the probe connector needs to be reseated or cleaned, there may be no parts cost, though a service call fee typically applies. Replacing the temperature probe itself generally costs between $40 and $120 for the part, plus labor. If the wiring harness requires replacement, total repair costs including labor can range from $150 to $400 depending on the specific oven model and service rates in your area.