Electrolux Dryer Error Code E31

The E31 error code on an Electrolux dryer indicates that the contact sensor is reporting a frequency reading that exceeds the expected operating range. The contact sensor, sometimes called a moisture sensor, works by measuring the electrical conductivity of laundry as it tumbles through the drum. When clothes contact the sensor bars, they complete a low-level circuit, and the control board interprets the resulting signal frequency to determine moisture content. If that frequency climbs too high, the board registers E31 and may interrupt or alter the drying cycle.

There are two primary causes for this fault. The first is a physical interference at the sensor itself. Lint buildup, fabric softener residue, or a foreign object lodged against the sensor bars can create a false or continuous electrical signal, driving the frequency reading out of the normal range. The sensor bars are typically located inside the drum near the lint filter opening, making them accessible for inspection. A thorough visual check and cleaning of the sensor surface is always the recommended starting point.

If the sensor and its wiring check out cleanly, the fault points to the electronic control board. The control board is responsible for generating the reference signal, interpreting the sensor return frequency, and triggering the error when values fall outside programmed thresholds. A defective board may misread valid sensor input or generate an internally corrupted signal, producing an E31 code even when the sensor itself is functioning correctly. In this scenario, replacing the control board is the appropriate repair.