Electrolux Range Error Code E77

Error code E77 on an Electrolux range indicates a break or open-circuit condition in the heat sink temperature sensor associated with the right cooking zones. The heat sink sensor is a thermistor that monitors the thermal state of the induction generator board's power components. When this sensor circuit is interrupted, either through a failed sensor, broken wiring, or a damaged connector, the control board cannot verify safe operating temperatures for the right side cooking zones and triggers E77 to halt operation and prevent potential overheating damage.

The right cooking zones generator board is the primary component responsible for producing the high-frequency power that drives the right-side induction elements. This board contains integrated heat sink monitoring to protect its internal MOSFETs and other power electronics from thermal runaway. A break in the sensor circuit reads as an infinite resistance condition, which the control system interprets as a fault rather than a valid temperature reading. This distinguishes a sensor break from an overtemperature fault, where the sensor is still functional but reporting excessive heat.

The most direct diagnostic path, consistent with the service data for this code, is replacement of the right side cooking zones generator board. This is because the sensor is typically integrated into or closely associated with the generator board assembly rather than being a fully separate, independently replaceable component. Before replacing the board, a technician should inspect the wiring harness and connectors between the generator board and the main control board for visible damage, corrosion, or loose pins, as a wiring fault can produce the same open-circuit reading without requiring board replacement.