On this page
Start here
Quick answer
A Thermador dishwasher that leaves water behind should be checked from the outside in: finish or cancel the cycle, inspect the sink-side drain path and air gap, then clean the filter and use the owner's manual for any pump-cover access. A blocked drain hose, disposal connection, filter, or pump can look similar. If water remains after the documented checks, or there is a leak or electrical hazard, stop and arrange service.
Work through in order
Diagnostic checks
Use only checks that match the exact appliance or system and its official guide.
-
Check 1
Record the cycle state and look for standing water in the tub without reaching into the pump. If the controls respond, select CANCEL / DRAIN as documented for the model.
Expected result: The tub drains, drains partially, or remains full; a display message is present or absent.
Next step: Continue with the sink-side and filter checks only while the appliance is safe and stable.
Why this matters
Why: A successful drain cycle moves the symptom toward a prior interrupted cycle. Persistent water keeps a blockage or pump problem in scope.
-
Check 2
Inspect the visible sink connection, garbage-disposal inlet, and air gap for blockage. If the dishwasher drains into a disposal, verify the dishwasher inlet plug was removed during installation; do not disconnect a pressurized water line.
Expected result: The sink or air gap is blocked, the disposal inlet is still plugged, or the visible drain path is clear.
Next step: Clear only the visible sink-side obstruction, then run the documented drain program once.
Why this matters
Why: A sink-side obstruction can prevent the dishwasher from emptying even when its pump is working. A clear connection shifts attention to the hose, filter, or pump.
-
Check 3
With power isolated as the owner's manual requires, remove and rinse the dishwasher filter using the manual's procedure. Inspect the visible drain hose for a kink and confirm its installation has the required high loop.
Expected result: The filter is coated with debris, the hose is kinked or poorly routed, or both are clear.
Next step: Reinstall the filter securely and correct only an obvious visible hose route; do not dismantle the drain pump unless the exact manual authorizes that access.
Why this matters
Why: Debris on the filter and a restricted or incorrectly routed hose can limit pumping. A clear filter and hose do not prove that the pump is serviceable.
-
Check 4
If the manual provides a pump-cover check, remove standing water with a ladle and follow that model procedure to inspect for loose debris. Do not probe the pump with tools or force the impeller.
Expected result: The manual-approved inspection finds debris, or the pump area is clear but the dishwasher still will not drain.
Next step: Run one documented drain test after reassembly. If it fails, arrange qualified Thermador service.
Why this matters
Why: A debris blockage can explain the symptom; a clear pump area with no drain leaves a pump, control, hose, or installation fault that cannot be identified safely from the symptom.
Use your observations
Decision map
Find the observation that best matches what you see, then follow the next safe action.
-
PATH 01Next step
What you see
Water drains after CANCEL / DRAIN and the sink-side path is clear.
Do this next
Use the exact manual for normal reset and monitor the next cycle; stop if water returns or leaks.
Why this path and its safety boundary
Why it matters: The original cycle may have been interrupted; a persistent drain obstruction is less likely.
-
PATH 02Next step
What you see
The sink, disposal inlet, or air gap is blocked, or the hose is visibly kinked.
Do this next
Clear the visible blockage or correct the visible hose route, then run the documented drain program once.
Why this path and its safety boundary
Why it matters: The external drain path can account for the standing water before a pump fault is considered.
-
PATH 03Next step
What you see
The filter and visible hose are clear but water remains, or the manual-approved pump check finds no debris.
Do this next
Stop home troubleshooting and arrange qualified service with the model number and cycle behavior.
Why this path and its safety boundary
Why it matters: The remaining possibilities include the drain pump, control, or concealed hose path; the source does not support a universal part diagnosis.
Helpful context
Understand the symptom
Start by preserving whether the dishwasher finished washing but left standing water, or whether it stopped with an error. The drain path includes the sink-side connection, air gap or disposal, hose, filter, and pump, so each observation changes the next check.
Thermador directs owners to the exact manual for filter removal and pump unblocking. Do not reach into a wet pump area or remove a cover without following that model procedure.
When checks do not resolve it
Need a professional?
Use qualified Thermador service when the drain path and filter are clear but water remains, the pump or control is suspected, the dishwasher leaks, or internal access is required. Keep the model, cycle state, and any displayed code for the technician.
Common questions
FAQ
Why is my Thermador dishwasher still full of water after a cycle?
Check whether the cycle was interrupted, then inspect the sink-side drain path, air gap or disposal inlet, filter, and visible hose route. Use the exact manual for pump access; persistent water needs service.
Can I remove the Thermador dishwasher drain pump cover?
Only if the exact owner's manual documents that user check and power is isolated as instructed. Do not probe or force the pump; use service if the blockage is not clearly accessible.
Does a high loop matter when a Thermador dishwasher will not drain?
Yes. Thermador's troubleshooting page says the drain hose needs the installation-specific high loop to pump properly. Verify the routing against the installation instructions for your model.
Read the exact guide
Official sources
- Dishwashers - TroubleshootingThermador · Thermador dishwasher drain lines, pump debris, filter cleaning, high-loop installation, and manual-specific service guidance
Community feedback
Share a repair observation
Share a plain-text repair observation. Accepted observations are published automatically; this page may take a moment to update.