Despite a high-quality name and performance, Thermador dishwashers can let you down sometimes. Thermador dishwasher not draining can result from blockages in several locations 一 most often the filter drain hose.
These blockages can prevent water from draining to the sink or disposal. But don’t think you are alone in this struggle. GE dishwasher and Kenmore dishwasher owners can face the same problem.
Removing those blockages can help in most cases. But sometimes, your need to resort to more complex solutions. In this article, we’ll review them to help you promptly fix the draining problem.
Why is your Thermador Dishwasher not Draining?
If you clean your Thermador dishwasher regularly, you’re less likely to face any draining problems. However, before determining the source of the issue, you most likely need to remove the puddle of water first.
To remove the standing water from your dishwasher, scoop it up with a cup or plastic container and absorb the remains with a towel or sponge.
Once you remove all standing water, you can start troubleshooting the issue. And that’s what we’ll do next.
1. Dirty filter
Since a dirty filter is one of the most common reasons for the Thermador dishwasher not draining, you need to check it first. The filter is responsible for screening out food particles to prevent them from clogging the drain pump.
But without regular cleaning, the dishwasher filter can become clogged with debris, resulting in water not draining. Dirty dishes and foul odor can be a sign of a dirty filter as well.
2. Clogged drain hose
The drain hose is the second thing to check when the Thermador dishwasher won’t drain. The clogs block the flow of the water through the drain hose resulting in the water returning into the dishwasher tub.
These clogs often consist of large food particles and an accumulation of debris. You can find them near the connection of the hose at the disposal, sink, or drain pump.
3. Defective drain pump
If you’ve checked the dishwasher for clogs and there is none, but your Thermador dishwasher still doesn’t drain water, there might be an issue with the drain pump.
Using impellers, the pump expels the washer out of the dishwasher and into the drain hose.
So it’s possible that the drain hose or the impellers have failed, leaving your dishwasher unable to drain.
4. Defective drain valve
A water inlet valve is the other component of your Thermador dishwasher that can get clogged with debris over time. You have to keep an eye on this one too.
5. Improperly installed garbage disposer
If the garbage disposer had been installed recently, the drain plug might not have been removed. All garbage disposers come with a solid plug in the drain tube. If the dishwasher is not connected to the garbage disposer, the plug should be in the drain tube.
However, if the dishwasher is connected to the garbage disposer, you must remove the plug.
Besides, it might be clogged if you haven’t replaced the garbage disposer recently.
6. Check the ball
The check ball is a small plastic ball in the check valve that prevents water from returning to the dishwasher after being drained. If this ball gets stuck, the water won’t be able to drain through the check valve.
7. Clogged air gap
Last but not least reason why the Thermador dishwasher is not draining could be a clogged air gap. When it functions properly, the air inside prevents the drain hose from suctioning dirty water inside the dishwasher.
If the air gap gets blocked, you will have dirty water inside the dishwasher or kitchen sink.
How to fix a Thermador Dishwasher not Draining?
There’s no need to panic when your Thermador appliance doesn’t drain properly. In most cases, all you need is to remove the debris build-up in the components involved in the draining process.
Sometimes though, you might need to replace the entire dishwasher parts.
Skim through these solutions to help get your dishwasher to start draining again. But pay attention to the cleaning to prevent the issue from happening in the future.
1. Clean the dishwasher filter
To clean the Thermador dishwasher filter:
- Remove the bottom rack to access it at the base of your dishwasher.
- Unscrew the filter by turning it counterclockwise.
- Disassemble the cylindrical filter from the mesh screen and rinse them under running water.
- Use a bristle brush to scrub away lingering debris and reassemble the filter and screen.
Finally, replace the filter in its housing and lock it in place by twisting clockwise. Replace the bottom rack.
2. Clean the drain hose
To inspect the drain hose, disconnect it from the drain pump and sink. It is not a simple task. So if you need help with this, you better call for a professional Thermador dishwasher repair service.
But if you’re willing to try it, check the user manual for the steps.
You should move the dishwasher to access the pump and unclog the drain hose. Then check the hose for any visible blockages and remove them with a screwdriver or wire hanger.
If you see no clogs, disconnect the drain hose from the disposer or sink to access the blockages. Still, if you can’t reach the clogs, replace the drain hose.
3. Replace the drain hose
If the pump motor shows no signs of continuity and you can’t remove the clogs and kinks, you need to replace the drain hose.
For that, unplug the dishwasher from the power socket and slide it out from under the countertop first. Then disconnect the old drain hose from the pump and the garbage disposal, and attach a new one in the same manner.
However, you must consult the user manual first to learn what replacement hose to get.
If you’re not comfortable doing this yourself, call for a professional. But it will charge you around $150 for this job.
4. Inspect the garbage disposer
Even the best dishwashers can stop draining properly if the disposer unit contains unground food. So, sometimes, all it takes to get your Thermador dishwasher to work properly again is to run the garbage disposer.
It is a good habit to leave the water on and let the garbage disposer run additional 15 seconds after the food is gone. This cleared the remaining food that might otherwise clog the drain.
5. Clean air gap
The drain connection with the air gap is the least likely to cause problems. But sadly, it could be the reason for the draining issues sometimes.
To investigate the air gap, twist it counterclockwise, remove and then check for gunk. Use a stiff brush to clean the air gap, place it back and run the dishwasher cycle again. This should fix the issue.
6. Use vinegar and baking soda.
Clogs are the most likely reason for the water not draining properly from your dishwasher, and not so easily cleaned sometimes too. That’s why you have to get creative.
Vinegar and baking soda are a “folk remedy” for removing clogs. You must mix one cup of each vinegar and baking soda and pour the mixture into the standing water at the bottom of your dishwasher. Then leave it for about 20 minutes.
The water should start draining, so rinse with hot water and run the rinse cycle. This should help you loosen the blockages and debris, preventing draining.
Adrian is an ISCET licensed professional that has completed the National Appliance Service Technician Certification Exam and has the expertise to diagnose and repair any appliance. He is well-versed in the latest technologies and techniques and is always up-to-date on the latest industry standards.
