Thermador Dishwasher Error Code E25 — Drain Pump Blocked or Check Valve Stuck
What this means
Error E25 on Thermador dishwashers indicates a problem with the drain pump cover or the check valve inside the sump. This is closely related to E24 but specifically points to an obstruction at the pump level rather than the hose. The drain pump cover may have been reinstalled incorrectly after cleaning, or the rubber check valve (flap valve) that prevents backflow may be stuck in the closed position. This code can also appear if the pump impeller is jammed by a small foreign object.
Alternate codes: E:25
Step-by-step fix
3 stepsCheck the drain pump cover
Open the dishwasher and remove the lower rack. Remove the cylindrical drain filter by twisting counterclockwise. Below the filter, locate the drain pump cover — it is a flat or slightly raised cover in the sump area. Lift it out and check for debris underneath. Ensure the cover sits flat and locks into position when reinstalled.
On Thermador Star-Sapphire and Emerald series, the pump cover has a specific orientation — there is usually an arrow or alignment tab that must match the housing.
Inspect and free the check valve
With the pump cover removed, look for the rubber check valve (flap valve) inside the sump. It should swing freely when pushed with a finger. If it is stuck, gently work it back and forth to free it. Clean any calcification or food residue that is preventing it from opening.
Hard water areas frequently see calcium deposits on the check valve. Soaking a cloth in white vinegar and holding it against the valve for a few minutes can dissolve buildup.
Clear any pump impeller obstructions
With the check valve area accessible, check if you can see or feel the pump impeller. Remove any small objects (glass, pits, toothpicks) that may be jamming it. The impeller should spin freely when nudged.
Some Thermador models require removing a small Torx screw to access the pump impeller area. Have a T20 Torx driver ready.
When to call a professional
If the check valve is cracked or the pump impeller is broken, professional replacement of the sump/pump assembly may be needed.
Related error codes
Information compiled from manufacturer service manuals, official troubleshooting documentation, and appliance repair industry resources. This guide is for informational purposes only — always consult a qualified technician for complex repairs.
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