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Troubleshooting Dishwasher

Thermador Dishwasher Not Draining: Causes and Fixes

Why your Thermador dishwasher won't drain and how to fix it. Step-by-step guide for E24/E25 error codes, clogged filters, and pump issues.

Updated Jun 2, 2026 5 min read
Why your Thermador dishwasher won't drain and how to fix it. Step-by-step guide for E24/E25 error codes, clogged filters, and pump issues.

Why your Thermador dishwasher is not draining

A Thermador dishwasher not draining is the most common service call we receive. Error codes E24 and E25 both point to drain system problems, but the root causes differ. E24 means water is draining too slowly; E25 means the pump impeller is physically blocked. Before calling for service, there are several checks you can perform yourself.

Step 1: Clean the drain filter

The drain filter sits at the bottom of the wash tub. Turn it counterclockwise to remove, rinse under running water, and use a soft brush to clear trapped debris. This single step resolves roughly 70% of Thermador dishwasher drainage issues. Reinsert the filter, run a rinse cycle, and check if drainage improves.

Step 2: Check the drain hose

The drain hose connects the dishwasher to your sink drain or garbage disposal. Pull the dishwasher forward enough to access the hose. Look for kinks, sharp bends, or compression from the countertop. Straighten any restrictions. If connected to a garbage disposal, verify the knockout plug inside the disposal inlet was removed during installation — a forgotten plug completely blocks drainage.

Step 3: Inspect the drain pump

Remove the drain filter and the pump cover beneath it (twist counterclockwise). Look for glass shards, bone fragments, or small utensil pieces jamming the impeller. The impeller should spin freely by hand. Reassemble and test.

When to call a professional

If the filter is clean, the hose is clear, and the impeller spins freely, but E24 or E25 persists, the drain pump motor itself has likely failed. Thermador uses a brushless DC drain pump that requires an exact OEM replacement. Schedule a service appointment — our technicians carry these parts and can typically complete the repair in a single visit.

Frequently asked questions about Thermador dishwashers
How loud are Thermador dishwashers?
Star Sapphire models operate at 39 dBA — quieter than a library. Emerald at 42 dBA, Sapphire at 44 dBA. All are among the quietest dishwashers available.
What is CrystalDry and do I need it?
CrystalDry uses natural zeolite minerals to absorb moisture and generate heat during the drying cycle. It produces bone-dry results — even on plastics — without a heated dry element. If you regularly wash plastic containers, it’s a significant upgrade over condensation drying.
Are Thermador dishwashers panel-ready?
Yes — all Thermador dishwashers accept custom cabinetry panels for a seamless kitchen look. Panel weight must stay within specifications to prevent hinge and latch wear.
How often should I clean the drain filter?
Monthly. This prevents most E24/E25 drain error codes and maintains wash performance.
Can I use any detergent?
Use quality dishwasher detergent tablets — never liquid dish soap, which creates excessive suds and can damage the pump.

Important notes for Thermador dishwasher owners

  • Always use genuine OEM parts — aftermarket components may fit but can compromise performance, safety, and warranty coverage on Thermador appliances
  • Never ignore error codes — Thermador codes are diagnostic aids designed to prevent small issues from becoming major failures. Address them promptly
  • Keep your owners manual accessible — it contains model-specific maintenance schedules and troubleshooting trees. Digital versions are available on the Thermador official site
  • Document issues before calling — note error codes, symptoms, when they started, and patterns. This helps the technician diagnose faster
  • Use surge protectors — power fluctuations damage electronic control boards. A quality surge protector protects your investment

When DIY troubleshooting is not enough

Some Thermador dishwasher issues can be resolved with the steps in this guide. However, call a certified technician immediately if you encounter:

  1. Gas smell (gas models) — turn off the appliance, open windows, leave the house, call from outside
  2. Burning smell or smoke — disconnect power immediately. Do not use until inspected
  3. Electrical sparking — turn off at the circuit breaker. Wiring or component failure
  4. Water leaking inside walls — shut off supply and call to prevent water damage
  5. Error codes that return after power reset — persistent codes indicate real component failure
  6. Sealed system issues — compressor, refrigerant work requires EPA-certified technicians

Schedule service online — our factory-certified Thermador technicians carry genuine OEM parts and serve all 50 states with a 30-day labor warranty.

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