Why Is My Bosch Dishwasher Not Draining?
Although Bosch dishwashers are well-built, one of the most common complaints we receive is about standing water in the tub. The drainage system on a Bosch goes through several components in order, and any one of them can cause the same symptom.
Before calling for service, there are a few things you should check yourself. Following that, a technician can diagnose it during a single visit.
Bosch Dishwasher Has Water in the Bottom After Cycle
Bosch dishwashers typically have a small amount of water (less than an inch) at the bottom of the tub. It prevents the pump seal from drying out. If you see more than that, or if the water is deep enough to reach the door seal, you have a drainage issue.
Clogged filter. This is the most common cause by far. Bosch uses a manual-clean filter (no self-cleaning chopper), which means food particles accumulate in the cylindrical filter at the bottom of the tub. Clean it every 1–2 months: twist and lift the filter assembly out, rinse it under running water with a soft brush. Takes two minutes.
Blocked drain hose. The hose that carries water from the pump to the sink drain can kink, sag, or clog with debris over time. If the filter is clean and you still have standing water, the hose is the next thing to check.
Air gap or garbage disposal issue. If your dishwasher drains through a garbage disposal or an air gap fitting, a clog there backs water into the dishwasher. If the disposal hasn’t been run recently, run it before calling for service — this fixes the problem more often than you’d expect.
Drain pump failure. When the filter and hose are clear, the pump motor is usually the culprit. The pump physically pushes water out through the drain hose. When the impeller wears or the motor fails, water stays in the tub. You’ll sometimes hear a humming sound during the drain cycle — that’s the motor trying to run with a jammed impeller.
Bosch Dishwasher Not Draining and Shows an Error Code
When a problem is detected, Bosch dishwashers display error codes. The most important ones for draining:
E24 — Drain hose kinked, clogged, or incorrectly installed. Check the hose routing first.
E25 — Drain pump blocked or impeller jammed. Usually food debris or a broken piece of glass caught in the pump. Clear the obstruction at the pump inlet before anything else.
E23 — Drain pump electronics fault. If E25 clears after cleaning and E23 shows up next, the pump motor itself needs replacement.
To reset the error, hold the Start button for 3-5 seconds to cancel the current cycle, then manually remove any standing water, inspect and clean the filter, and start a new cycle. If the same code appears again, the underlying problem persists, and a technician must diagnose it.
Bosch Dishwasher Not Draining After the Cycle Ends
If the machine runs a full cycle but water is still sitting in the tub when you open the door:
- Run the disposal (if connected to one)—a full disposal blocks the shared drain
- Check the drain hose for a high loop — Bosch recommends the hose loop up to cabinet height before dropping to the drain; without it, water can siphon back in
- Listen during the drain portion of the next cycle — you should hear a low hum from the pump for 90–120 seconds; silence during that window usually means the pump isn’t activating
Bosch Dishwasher Not Draining Completely — Small Amount Left
If most water drains but a shallow pool remains:
Partially clogged filter or drain hose. Enough debris to slow drainage but not stop it entirely. Full cleaning usually resolves this.
Check valve worn. The check valve (also called a drain flapper) prevents water from flowing back into the tub after the pump stops. If the rubber flap is worn or stuck open, a small amount of water re-enters the tub after the drain cycle. This is a straightforward part replacement.
Can I Force a Bosch Dishwasher to Drain?
Yes. On most Bosch models you can force a drain cycle:
- Press and hold the Start button for 3–5 seconds to cancel the current program
- The dishwasher will pump out any remaining water
- Once the drain cycle finishes, open the door and check how much water remains
If the water still does not move after the forced drain, the pump or drain path is clogged and requires physical inspection. Don't keep running cycles; you're simply pushing the pump harder against an obstruction.
Recent Service Call: Bosch Dishwasher Not Draining in Evanston
We received a call from a homeowner in Evanston. For the past two weeks, their Bosch Series 500 dishwasher had left standing water at the end of each cycle. They had already cleaned the filter—it was clear—and the disposal was working properly.
When our technician Yurii opened it up, the drain pump impeller was jammed with a fragment of broken glass, most likely from a broken glass that went through a cycle unnoticed. One of the impeller's fins had cracked. The pump was still running — barely — so some water drained but not all of it.
Yurii replaced the drain pump assembly. The dishwasher drained completely during the first test cycle. The total repair time on-site is approximately 45 minutes.
If you’ve cleaned the filter and the disposal is clear but the dishwasher still isn’t draining, that’s almost always a pump issue — and it’s a repair, not a replacement.
