Bosch Dryer Error Code E:3

The E:3 error code on a Bosch dryer indicates that the condensate collection system has detected a full or malfunctioning condition. Bosch condenser dryers extract moisture from the drum airflow and collect it as liquid water, either in a removable condensate tank or by routing it through a drain hose. When the control system detects that the tank or base group reservoir has reached capacity, or that a fault exists in the drainage pathway, it triggers E:3 to halt operation and prevent overflow or water damage.

The base group is a sealed lower assembly that houses the condensate pump, collection reservoir, and level-sensing electrodes. These electrodes detect the presence of water by measuring conductivity between two contact points. If the electrodes become coated with mineral deposits, lint, or detergent residue, they can send a false full signal to the control board even when the reservoir is not actually at capacity. This is one of the most frequent causes of a recurring E:3 code after the tank has already been emptied.

The condensate pump is responsible for moving collected water out of the base group reservoir and up into the removable tank or drain line. If the pump is blocked by lint accumulation or debris, or if the connected hoses are kinked, clogged, or improperly routed, water will back up in the base group and trigger the error. Diagnosing E:3 follows a logical sequence: emptying the tank first rules out a legitimate full condition, followed by electrode cleaning to address false readings, and finally pump and hose inspection to identify mechanical blockages.