Cormac Hale Key Takeaways
- A small amount of water in the sump is normal after a cycle
- Clogged filters are the most common cause of incomplete draining
- The drain hose can kink or clog, blocking water flow
- E22 and E24 error codes point directly to filter or drain issues
The Bottom Line
Most Bosch dishwasher drainage problems start with a clogged filter or blocked hose. Clean the filter monthly and check the drain hose for kinks. If errors persist, contact a certified technician.
Is It Normal to Have Water in the Bottom?
Here's something most people don't realize. A small puddle in the dishwasher sump after a cycle is completely normal. Bosch designs their dishwashers to retain a small amount of water in the base to keep the seals lubricated.
The problem starts when you open the door and find the filter area completely flooded or more than an inch of standing water. That's not normal. That's a clog, a blockage, or a pump issue.
What to look for:
If water rises to the bottom of the door or pools around the filter screen after every cycle, something is blocking the drain path. This won't fix itself.
What Causes a Bosch Dishwasher to Stop Draining?
Drain problems in Bosch dishwashers almost always trace back to three places. The filter, the drain hose, or the pump. Here's how each one fails.
1. The Filter Is Clogged
This is the number one cause. Food particles, grease, glass shards, and soap residue build up in the filter over time. When the filter clogs, water has nowhere to go so it sits in the basin.
Bosch dishwashers have two filters. A cylindrical mesh filter and a flat plate filter underneath. Both need cleaning. If you never cleaned them, that's probably your issue.
2. The Drain Hose Is Blocked or Kinked
The drain hose carries water from the dishwasher to the sink drain or garbage disposal connection. Over time, debris collects inside the hose. A kink in the hose from improper installation also blocks flow.
Check where the hose connects to your sink drain or disposal. If the connection is clogged, water backs up into the dishwasher. Also verify the hose has a proper high loop installed under the sink.
3. The Drain Pump Is Faulty
If the filter is clean and the hose is clear, the drain pump itself might be failing. You might hear a humming noise when the cycle ends, or no noise at all. A failed pump won't push water out.
Pump issues are less common than clogs, but they happen. A tech can test the pump motor and check for obstructions in the impeller.
What the Error Codes Mean
| Code | Meaning | What to Do |
|---|---|---|
| E22 | Filter blocked | Remove and wash filter under running water |
| E24 | Drainage blocked or pump issue | Clear hose and pump; check for kinks |
Verify these codes against your model's manual. Some older models may display variations. If you see E15, that means water in the base pan from a leak. Turn off the water supply and call for service immediately.
How to Fix It: Step by Step
Before opening panels or reaching inside, unplug the dishwasher. Safety first.
Step 1: Clean the Filter
Remove the bottom rack. Twist and lift out the filter unit at the base of the tub. Unscrew the cylindrical filter from the flat plate filter.
Rinse both under hot running water. Use a soft brush to scrub stuck-on residue. Reassemble and reinstall.
Do this once a month. It takes five minutes and prevents most drainage issues.
Step 2: Check the Drain Hose
Pull the dishwasher out slightly (or access from under the sink). Trace the drain hose from the dishwasher connection to the sink drain or disposal. Look for kinks, sharp bends, or soft spots. Straighten any kinks.
Disconnect the hose and run water through it to check for blockages. Reconnect securely.
Step 3: Inspect the Drain Pump
If the filter is clean and the hose is clear, the pump might have an obstruction. Glass shards, bone fragments, or fruit pits can jam the impeller. You can often access the pump cover and remove debris by hand.
If the pump is humming but not spinning, or making no noise at all, the motor may be failed. That requires professional replacement.
When to Call a Professional
You can handle filter cleaning and hose checks yourself. Those are straightforward. But if you've cleaned everything and the dishwasher still won't drain, stop there.
Pump motor replacement involves removing internal components, handling electrical connections, and reassembling the sump assembly. That's certified technician work. An improper repair can cause leaks, electrical faults, or void your warranty.
Under Magnuson-Moss Warranty Act rules, using an independent technician or aftermarket parts cannot void your warranty by itself. The manufacturer must prove that specific repair caused the problem. Keep your receipts.
Maintenance Tips to Prevent Future Problems
- Scrape plates before loading. Don't rinse them spotless, but remove bones, pits, and large food chunks. Use a dishwasher cleaner tablet once a month to cut grease buildup.
- Run the garbage disposal before starting a wash cycle if your dishwasher connects to one. A backed-up disposal pushes water back into the drain hose.
- Check the spray arms regularly. Clogged holes reduce water pressure and can cause poor drainage. Poke out debris with a toothpick.