Bosch Dishwasher Drain Pump Replacement — E24/E25 Diagnosis and BSH OEM Sourcing

The drain pump in a Bosch dishwasher sits at the lowest point of the sump assembly, drawing water from beneath the triple-filter system and pushing it through the drain hose to the disposal or standpipe. Bosch uses a synchronous motor pump (BSH 00631200 for most 300/500 Series units) — a design where the motor runs at a fixed speed determined by the AC frequency rather than varying with load. This gives consistent drain performance but means the pump either works at full capacity or does not work at all. There is no gradual degradation — when the motor winding fails or the impeller jams, drainage stops immediately.

This all-or-nothing behavior is why Bosch's E24 and E25 drain error codes are among the most frequently reported by homeowners. E24 indicates the drain hose is kinked or clogged. E25 indicates the drain pump cover is not seated correctly or the impeller is obstructed. However, both codes can also appear when the pump motor itself has failed — the board cannot distinguish between a mechanical obstruction and an electrical motor failure because it monitors drain success by timing how quickly the sump empties, not by measuring pump motor current directly.

Diagnosing the Drain Pump Before Replacing It

Before purchasing a replacement pump, rule out the non-pump causes of E24/E25:

• Check the drain hose — Bosch dishwashers use a high-loop or air-gap drain configuration. The hose must loop up to at least the underside of the countertop before descending to the drain point. A hose that sags creates a water trap the pump cannot overcome. Common after installation or kitchen remodeling
• Remove and inspect the drain pump cover — The cover sits inside the sump at the bottom of the tub. Twist it counterclockwise and pull up. Glass shards, food debris, and toothpicks commonly lodge in the impeller chamber. Remove any obstructions, reseat the cover, and run a drain cycle
• Test the pump motor electrically — Disconnect the pump's 2-pin connector (accessible from under the unit after removing the bottom panel with two Torx T20 screws). Measure resistance across the motor terminals: a healthy Bosch drain pump reads 150–250 ohms. An open circuit (infinite resistance) confirms a failed motor winding. A very low reading (under 50 ohms) indicates a shorted winding
• Listen for the pump during a drain attempt — Start any cycle and wait for the drain phase. A working pump with an obstruction hums loudly. A dead pump produces no sound at all during the drain phase — the unit simply sits with water in the tub

If the pump motor reads correct resistance but still does not drain, check the pump connector pins at the control board end for corrosion. The connector sits near the bottom of the board where condensation collects.

Cost Breakdown

The Bosch drain pump is a standardized component across many models — BSH part number 00631200 fits a wide range of 300 and 500 Series units manufactured from 2014 onward. The 800 Series uses a variant with a slightly different mounting bracket. Always confirm the exact BSH part number from your model's tech sheet (located inside the door panel or available from BSH's online parts lookup using the E-number from the rating plate).

Accessing and Replacing the Pump

The drain pump is accessed from underneath the dishwasher. On built-in installations, this means partially pulling the unit out from the cabinet:

1. Kill power at the breaker. Shut off the water supply valve under the sink
2. Disconnect the drain hose from the disposal/standpipe connection under the sink — have towels ready, as residual water will drain
3. If hardwired, disconnect the electrical supply at the junction box under the unit
4. Remove the two Torx T20 screws at the bottom of the kick plate and slide it forward to remove
5. Remove the three Torx T20 screws securing the unit to the countertop (top corners and center)
6. Carefully slide the dishwasher forward approximately 12 inches — enough to access the underside. Protect the floor with cardboard
7. The drain pump sits at the bottom-left of the sump housing. It attaches with a quarter-turn bayonet mount — rotate counterclockwise approximately 30 degrees and pull down
8. Disconnect the 2-pin electrical connector from the pump
9. Note the orientation of the pump outlet — it must point toward the drain hose connection on the replacement
10. Seat the new pump into the bayonet mount and rotate clockwise until it clicks. Reconnect the 2-pin connector
11. Slide the unit back, reattach countertop screws and kick plate, reconnect water and drain lines, restore power
12. Run a rinse-only cycle to verify drainage and check all connections for leaks

Important note about the drain pump cover: The cover inside the tub (accessible from the interior) serves as a pre-filter for the pump impeller. If the cover gasket is cracked or the cover threads are stripped, replace it simultaneously — a leaking cover allows debris to bypass filtration and reach the new pump's impeller.

AquaStop Interaction with Drain Failures

When a failed drain pump allows water to sit in the sump indefinitely, slow evaporation and minor gasket seepage can eventually deposit enough moisture in the base pan to trigger the AquaStop float switch (E15). This creates a confusing double-fault scenario: E24/E25 from the drain failure plus E15 from the resulting water accumulation. The correct repair sequence is to replace the drain pump first, then tilt the unit to drain the base pan. Replacing the AquaStop hose in this scenario is unnecessary — the hose did not fail; the leak protection system worked exactly as designed.

Pump Lifespan and Failure Causes

Bosch drain pumps last 7-12 years under normal residential use. The synchronous motor is inherently robust because it has no brushes to wear. Common failure causes:

• Glass fragment impeller damage — broken glass shards pass through the filter system and wedge between the impeller and housing, scoring the impeller blades and eventually seizing the motor
• Hard water scale buildup — mineral deposits accumulate on the impeller and housing walls, reducing clearance until the impeller drags and overheats the motor winding
• Thermal damage from running dry — if the filter system is removed and the machine is run, debris rapidly clogs the pump. The motor overheats attempting to push through the blockage
• Electrical surges — the pump motor winding is sensitive to voltage spikes that exceed its insulation rating

Preventing Premature Pump Failure

• Clean the drain pump cover (inside the tub) monthly — twist counterclockwise, remove, rinse under running water, inspect the gasket, replace
• Never run the dishwasher without the triple-filter assembly in place — unfiltered debris destroys the impeller within weeks
• Scrape dishes before loading to reduce the burden on the filter system — Bosch's filtration handles normal food residue but not bones, fruit pits, or glass fragments
• Check the drain hose high-loop during annual maintenance — a sagging loop forces the pump to work harder and shortens motor life

FAQ

What does E24 mean on a Bosch dishwasher?

E24 indicates a drain blockage — the control board detected that the sump did not empty within the expected time. Check the drain hose for kinks, inspect the drain pump cover for debris, and test the pump motor resistance (should read 150–250 ohms). E24 does not always mean the pump itself has failed.

Can I clean the Bosch drain pump without removing it?

Yes — the drain pump cover inside the tub gives access to the impeller chamber without pulling the unit out. Twist the cover counterclockwise, remove it, and clear any debris visible in the impeller area. This resolves many E24/E25 errors caused by obstructions rather than motor failure.

How long does it take to replace a Bosch dishwasher drain pump?

The repair takes 45-90 minutes including pulling the unit partially out of the cabinet. The pump itself attaches with a quarter-turn bayonet mount, making the actual swap quick — most of the time is spent on access and reconnecting utilities.

Is the Bosch drain pump the same across all models?

BSH part number 00631200 fits most 300 and 500 Series units from 2014 onward. The 800 Series uses a variant with a different mounting bracket. Always verify the exact part number from the tech sheet inside the door panel or BSH's online parts lookup.

---

Bosch dishwasher not draining? Our technicians diagnose E24/E25 errors on site and carry OEM drain pumps for same-day repair. Book a technician →