Zanussi Dishwasher Error I21
⚡ Quick Answer: The Zanussi Dishwasher error I21 indicates a malfunction in the drain pump, often characterized by slow or no drainage and standing water in the tub. ... ✅ DIY Fixable
What Does Error I21 Mean?
The Zanussi Dishwasher error I21 indicates a malfunction in the drain pump, often characterized by slow or no drainage and standing water in the tub. This issue typically stems from a partially blocked drain hose or filter, which may lead to unusual noises during operation. Resolving this problem often requires cleaning the external drain components.
Common Symptoms:
- Dishwasher displays code I21
- Water drains slowly or not at all
- Standing water visible in dishwasher tub
Possible Causes
- Drainage obstruction (partially blocked drain hose or filter) (medium)
- Foreign object or non‑return valve issue in drain system (low)
How to Fix Error I21
DIY Fix Check and clean external drain components
- Turn off and unplug dishwasher.
- Remove and clean the dishwasher drain filter to clear debris.
- Check the sink trap and drain hose for kinks or visible blockages.
- Reattach everything and run a short rinse cycle to test drainage.
Technician Only Inspect and clear internal drain path and pump
- Disconnect dishwasher power and water supply.
- Remove access panel and locate drain pump and non‑return valve.
- Inspect and remove any obstructions within drain pump and non‑return valve.
- Check drain hose routing and flush with water if necessary.
- Reassemble and test operation.
Parts needed: Drain hose, Non‑return valve, Drain pump
- If the dishwasher still fails to drain after cleaning filters and hoses
- If unusual noises come from pump area
- If water leakage occurs
Next step
Choose the next step for I21
Confirm the diagnosis before ordering. An error code can identify the system involved, but it does not prove that a specific part has failed.
Most relevant component to inspect
Drain Hose
Carries waste water from the drain pump to your home's standpipe or sink drain.
- Typical part-only price
- $15 - $30
- DIY difficulty
- Easy
- Estimated time
- 15-30 mins
Where can I find the model number?
Check the rating label around the door, lid, frame, rear panel, or inside the appliance cabinet. Use the complete model number, including suffixes.
Verify the complete model and part number on the retailer's compatibility page before ordering.
Other parts options
Check related components first; use model search as a fallback.
Drain Pump
Pumps waste water out of the appliance during the drain cycle.
Model-compatible Dishwasher parts
Enter the complete model number to browse compatible replacement parts. This is a model-based parts search, not a diagnosis that a specific component failed.
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Optional routine care
Maintenance supplies
These products support cleaning or routine upkeep. They are separate from the possible repair components above and are not claimed to fix this error code or symptom.
Dishwasher Cleaner and Descaler
Supports routine removal of mineral scale, grease, and odor. It is maintenance, not a repair for a failed pump, valve, or control.
Braided Dishwasher Inlet Hose
For replacement of an externally damaged supply hose. Verify connection size, length, and appliance installation requirements before ordering.
Affiliate disclosure: As an Amazon Associate I earn from qualifying purchases. Recommendations are based on routine-care relevance, not commission rate.
Technical Specifications
| note | The previous model-independent part specification was removed. Verify the full model number and diagnosis in the manufacturer's official parts catalog before ordering. |
|---|---|
| part_number | None |
Common Questions
What does I21 error mean on Zanussi Dishwasher?
I21 error indicates a drainage malfunction, often due to a blocked drain hose or filter.
Can I fix Zanussi Dishwasher I21 error myself?
Yes, you can check and clean the drain filter and hose to resolve the issue.
How much does it cost to fix I21 error?
Repair costs range from $50 to $150, depending on the nature of the blockage.
When should I call a technician for I21?
Call a technician if the issue persists after cleaning or if you hear unusual noises.
Sources & References
- Zanussi Dishwasher Error Codes General Info (official)
Data last verified: 2026-07-31
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