Wolf Oven Error Code E26/F3

The E26/F3 error code on a Wolf oven indicates an open circuit condition in the 300C temperature sensor. This sensor is a thermistor or resistance-based probe responsible for monitoring oven cavity temperature at a specific range around 300 degrees Celsius. An open circuit means the control board is receiving no signal from the sensor, either because the sensor itself has failed internally, or because the electrical circuit connecting the sensor to the control board has been interrupted somewhere along the wiring path.

The primary diagnostic step is to measure the resistance of the 300C temperature sensor directly at the sensor terminals. A functioning sensor will produce a readable resistance value consistent with its temperature coefficient curve. If the sensor reads infinite resistance or open loop (OL) on a multimeter, the sensor element has broken internally and the component requires replacement. If the sensor reads within a normal range, the fault lies in the wiring harness, connectors, or the control board input circuit rather than the sensor itself.

Common contributors to this fault include heat-related degradation of the sensor probe over time, damaged wiring insulation from prolonged exposure to oven temperatures, and corroded or loose connector pins at either the sensor or control board end. Because the 300C sensor monitors a high-temperature range, both the sensor and its associated wiring are under continuous thermal stress during normal oven operation, making them susceptible to gradual failure.