Editorial & technical review
- Written by ApplianceWorth Editorial Team
- Technically reviewed by Victor — appliance technician
- Last reviewed 2026-07-01
- Applies to Bosch dishwashers
- Confidence medium
- Also displayed as E20
- Sources Manufacturer service documentation and field-repair experience · Methodology · Report a correction
What this code means
These codes point to the circulation or heat-pump system. E20 generally indicates an electrical or functional pump fault, while E21 indicates that the pump is blocked or unable to circulate water.
Most likely causes
- The circulation pump is blocked by debris
- The pump motor or winding has failed
- The integrated heater/heat-pump assembly is defective
- A loose harness or power-module fault is preventing normal operation
Safe checks for the owner
- Turn off power and clean the filters and accessible sump area.
- Do not force the circulation-pump impeller or run the unit dry.
- Note whether the dishwasher fills but remains quiet, hums or stops shortly after starting.
Estimated U.S. repair cost
$450–$850, depending on model, access, parts availability and local labor.