Bosch E23 — Drain pump Triac fault — drain motor control circuit failure

What Bosch E23 error means on your dishwasher

Error code E23 indicates a fault with the drain pump control circuit on the main board. Specifically, the Triac (electronic switch) that controls the drain pump motor has failed — it may be stuck on (the pump runs continuously) or stuck off (the pump never activates). This is different from E24/E25 which indicate physical drain blockages. If you encounter the bosch e23 error, professional Bosch dishwasher repair may be needed.

Symptoms

• The drain pump runs continuously, even when the tub is empty
• The dishwasher won’t drain at all despite no visible blockage in the filter or drain hose
• E23 appears during the drain phase of any cycle
• You may notice a humming or buzzing sound from the base of the dishwasher

Common causes

• Triac failure on the control board — the electronic switch that powers the drain pump has short-circuited or burned out
• Drain pump motor failure — the motor itself has seized or has a shorted winding, which can also damage the Triac
• Wiring fault — damaged wiring between the control board and drain pump creates an open or short circuit

See all Bosch dishwasher error codes for related fault codes and diagnostic steps.

Troubleshooting steps you can try

1. Power reset — turn off the breaker for 5 minutes. If the Triac is in a temporary fault state, a reset may clear it.
2. Listen for the pump — start a cycle and listen during the drain phase. If the pump doesn’t make any sound at all, the issue is likely the pump or its power circuit.
3. Check for blockages anyway — clean the filter and check the drain hose for kinks, as a blocked pump can eventually damage the Triac.
4. Check Bosch support — visit Bosch’s official dishwasher support page for model-specific troubleshooting guides and tech notes.

When to call a technician

E23 almost always requires control board or drain pump replacement. A technician will test the drain pump motor resistance (typically 100–200 ohms) and check the Triac on the control board. If the Triac has failed, the entire control board needs replacement — individual Triac repair is not practical for field service. Codes may vary by model generation and series. Schedule a certified Bosch technician for fast, reliable diagnosis and repair.