The cycle runs, but the dishes come out with food still stuck on them. On a Thermador this almost always comes down to water not reaching the dishes — a clogged filter, blocked spray arms, or how it’s loaded — and most of it you can fix in minutes.
Rewashing everything by hand? Call 844-975-6696 or book a visit.
Quick guide
| What you’re seeing | Likely cause | Fix it yourself? |
|---|---|---|
| Food redeposited on dishes | Clogged filter | Yes — clean it |
| Top rack barely cleaned | Spray arm blocked or not spinning | Yes — clear the arms |
| Random dishes dirty | Overloading or blocked spray | Yes — reload |
| Nothing cleans well | Low water, cold water, or wash pump | Partly — check water |
Dirty vs. filmy — which problem is it?
First, pin down what you’re seeing. Food still stuck on dishes means the wash action isn’t reaching them — that’s this guide. Clean of food but coated in white film or spots is a detergent and water-chemistry issue instead — see why it leaves residue. The fixes are completely different.
What causes it
- Clogged filter. A dirty filter recirculates food particles back onto the dishes.
- Blocked spray arms. Clogged holes or arms that can’t spin leave whole areas unwashed.
- Overloading. Tall items and overlapping dishes block the spray from reaching everything.
- Water too cold or too little. Weak fill or cold water can’t dissolve detergent or cut grease.
- Wash pump. Less common — a weak wash pump doesn’t build enough spray pressure.
If the dishwasher isn’t filling properly in the first place, that’s the root cause — see why it won’t fill with water.
Step-by-step: what to check
- Clean the filter. Twist out the bottom filter and rinse it — the most common fix by far.
- Spin the spray arms. Make sure they turn freely and no tall item blocks them.
- Clear the spray holes. Poke out any debris blocking the little jets.
- Reload more loosely. Don’t nest or overlap dishes; keep tall items to the sides.
- Run the tap hot first. Run the sink until hot so the dishwasher starts with hot water.
- Use fresh detergent. Old or caked detergent doesn’t dissolve properly.
When to call a technician
Book a visit soon if the filter and spray arms are clean, loading and detergent are right, and dishes still come out dirty. That points to weak water flow or a failing wash pump, which is tested for pressure and continuity before replacement. Book Thermador dishwasher repair to find why the wash action is weak.
It can wait if cleaning the filter and arms fixed it — that’s normal upkeep, not a fault.
What the repair actually involves
A technician checks the filter, spray arms, and water temperature, then tests the wash pump for pressure and the water level for a proper fill. A worn spray arm or bearing is replaced (a defined part in the least-expensive category); a weak wash pump is the mid category. If the fill is short, the trail leads back to the inlet valve. The main cost driver is a spray arm versus the pump. You get a written estimate first, and common wash parts are stocked for a single visit.
Is it safe to use until then?
Yes — poor cleaning is an inconvenience, not a hazard. You can keep using it and rewash the odd item by hand until the wash action is restored.
Preventing it
- Scrape plates and clean the filter regularly.
- Don’t overload; leave room for the spray to reach every dish.
- Run a monthly hot cleaning cycle to keep the arms and filter clear.
Frequently asked questions
Q: Why are my dishes still dirty after a full cycle?
A: Almost always because water isn’t reaching them — a clogged filter, blocked spray arms, or overloading. Clean the filter and arms and reload more loosely; that fixes most cases. If not, the water flow or wash pump needs checking.
Q: Why isn’t my spray arm spinning?
A: Usually a tall item blocking it, debris in the bearing, or clogged spray holes reducing the jet that drives it. Clear the arm and its holes and check nothing overhangs it — it should spin with a light flick.
Q: Do I need to rinse dishes before loading?
A: Scrape off large scraps, but you don’t need to pre-rinse — modern detergents need some soil to work against. What matters more is a clean filter and not overloading, so the spray reaches everything.
Q: Does water temperature affect cleaning?
A: Yes — cold water won’t dissolve detergent or cut grease well. Running the kitchen tap until hot before starting a cycle means the dishwasher fills with hot water from the start, which noticeably improves results.
Get spotless dishes again
If the basics are covered and dishes still come out dirty, the wash action needs checking. We handle Thermador dishwasher repair with a written estimate before any work starts.
Call 844-975-6696 or book online. Same-day service is usually available in New York, Los Angeles, Chicago, San Francisco, Houston, and Miami.