Bosch Dishwasher E24 Error Code — Causes and Step-by-Step Fix

When your Bosch dishwasher displays the E24 error code, it means the appliance has detected a blockage in the drain hose system that prevents water from being pumped out of the tub. This is one of the most common error codes on Bosch dishwashers and affects models across their entire lineup — from the entry-level 300 Series to the premium Benchmark line.

Key Statistic: In 35% of E24 cases, the fix is simply straightening a kinked drain hose — a 5-minute repair with zero cost in parts.

Unlike some appliance error codes that require advanced diagnostics, the E24 is primarily a mechanical problem related to water flow restriction. This guide covers every possible cause, a complete step-by-step diagnostic process, and specific part numbers for replacement when needed. If you're also dealing with water pooling issues, you may want to review our guide on the Bosch Dishwasher E15 Error which covers leak detection problems. 121

What Does E24 Mean on a Bosch Dishwasher?

The E24 error code on a Bosch dishwasher specifically indicates a drain hose blockage. The dishwasher's control module monitors the drain pump operation and water level sensors during the drain phase. When the system detects that water isn't evacuating despite the drain pump running, it triggers the E24 fault.

Bosch uses a tiered error code system for drainage problems, and understanding the differences helps with accurate diagnosis:

• E24 — Drain hose blockage (water can't exit the machine through the hose)
• E22 — Filter mesh clog (water can't reach the pump because the internal filter system is blocked)
• E21 — Drain pump motor failure (the pump itself isn't operating correctly)
• E25 — Drain pump impeller cover issue (the check valve or pump cover is clogged)

The E24 code tells you the problem is downstream of the pump — meaning the pump is running and attempting to push water out, but the water has nowhere to go. This narrows the problem to the drain hose itself, the connection point at your sink or garbage disposal, or the plumbing configuration (particularly the high loop requirement).

On the technical level, Bosch dishwashers use a turbidity sensor and flow meter to confirm water is actually leaving the tub. When the drain pump runs for its allocated time but the flow meter registers minimal throughput, the control board stores E24 and halts the cycle with water remaining in the tub. 122

Common Causes of the Bosch Dishwasher E24 Error

Here are the documented causes of the E24 error code, ranked by frequency based on service data and technician reports:

1. Kinked or Blocked Drain Hose — 35% of Cases

The drain hose connects from the pump outlet at the bottom of the dishwasher to either a garbage disposal inlet, an air gap fitting, or a direct sink drain connection. Because the hose runs behind or beside cabinets in a confined space, it commonly develops kinks during installation, when items are stored under the sink, or if the dishwasher is pushed back too far after maintenance.

A blocked hose can also occur from internal buildup — grease, food residue, and soap scum gradually narrow the hose's internal diameter, especially at bend points. Hoses older than 5 years are particularly susceptible to this internal fouling.

2. Clogged Drain Filter System — 25% of Cases

Although technically E22 is the "filter clog" code, a severely blocked filter can reduce water flow enough to trigger E24 instead. The Bosch drain filter system consists of three components: a coarse filter (catches large debris), a fine mesh microfilter (part 00645038), and the filter housing. When these become saturated with food particles and grease, water cannot reach the drain pump efficiently.

3. Garbage Disposal Knockout Plug Not Removed — 15% of Cases

This is exclusively a new installation issue. When a garbage disposal is manufactured, the dishwasher inlet port is sealed with a plastic knockout plug. If the installer connects the dishwasher drain hose without first removing this plug from inside the disposal, water has literally nowhere to go. This is the #1 cause of E24 on newly installed dishwashers.

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Installation Alert: If your Bosch dishwasher shows E24 immediately after a new installation or garbage disposal replacement, the knockout plug is the most likely culprit. Check it before anything else.

4. Drain Pump Impeller Blocked — 12% of Cases

Small items like glass shards, fruit pits, broken plastic pieces, or bone fragments can pass through the filter system and lodge in the drain pump impeller. The pump motor still runs (so you won't get E21), but the impeller can't spin properly to push water through the hose. You may hear a strained humming or buzzing sound during the drain phase.

5. Missing High Loop in Drain Hose — 8% of Cases

Bosch requires that the drain hose be installed with either a high loop (the hose secured at the highest point under the countertop before dropping down to the drain connection) or an air gap device. Without this, dirty water from the sink can siphon back into the dishwasher, and the drain path doesn't maintain proper pressure differential for the pump to work correctly. The E24 can appear intermittently in this scenario.

6. Failed Drain Pump Motor — 5% of Cases

While a complete pump motor failure typically generates E21, a partially degraded pump motor that runs but lacks sufficient power to overcome any slight resistance in the drain path can trigger E24 instead. The pump (Bosch part 00620774) is rated for approximately 2,000–3,000 wash cycles before performance degradation. At 5 cycles per week, that's 8–12 years of service life. 123

How to Fix the Bosch Dishwasher E24 Error — Step by Step

Work through these steps sequentially. Most E24 errors resolve within the first three steps. Always disconnect power before accessing internal components.

Step 1: Inspect and Straighten the Drain Hose

1. Open the cabinet under your kitchen sink and locate the dishwasher drain hose (usually a corrugated gray or white hose)
2. Trace the hose from where it enters the cabinet to where it connects to the disposal or drain
3. Check for any kinks, sharp bends, or compression from items stored under the sink
4. Straighten any kinks and ensure the hose follows a smooth path
5. Verify the hose has a high loop — it should rise to the highest point under the countertop before descending to the drain connection
6. If no high loop exists, secure the hose at the top of the cabinet with a hose clip or zip tie

Step 2: Check the Garbage Disposal Connection

1. If connected to a garbage disposal, disconnect the drain hose from the disposal inlet
2. Look inside the disposal inlet port — if you see a solid plastic disc, the knockout plug was never removed
3. Remove the knockout plug by inserting a screwdriver and tapping it inward, then retrieve the disc from inside the disposal
4. If the knockout was already removed, check the inlet port for grease or food buildup and clean it
5. Reconnect the hose securely with the hose clamp

Step 3: Clean the Drain Filter System

1. Open the dishwasher and remove the lower spray arm (twist counterclockwise and lift)
2. Remove the cylindrical coarse filter by turning the handle counterclockwise
3. Lift out the fine mesh filter plate beneath it
4. Rinse both filter components under running water, using a soft brush to remove grease and debris
5. Inspect the filter housing sump for food particles or debris and clean thoroughly
6. Reassemble: place mesh filter first, then coarse filter, and lock by turning clockwise

Step 4: Flush the Drain Hose

1. Disconnect the drain hose from both the dishwasher pump outlet and the sink/disposal connection
2. Run water through the hose from both directions to flush any internal blockage
3. If water flows poorly, use a long flexible brush or snake to clear the interior
4. For heavy grease buildup, soak the hose in hot water with dish detergent for 30 minutes
5. Reconnect the hose securely at both ends, ensuring proper clamp tightness

Step 5: Inspect the Drain Pump Impeller

1. With filters removed, look into the pump housing (circular area at the bottom of the filter sump)
2. You may see the pump impeller cover — on many Bosch models this can be twisted off
3. Remove any debris blocking the impeller: glass, bones, plastic fragments
4. Spin the impeller gently with your finger — it should rotate freely in one direction
5. If the impeller is cracked, broken, or seized, the drain pump assembly needs replacement (part 00620774)

Step 6: Test the Drain Pump Electrically

1. Disconnect power to the dishwasher at the breaker
2. Access the pump from underneath — tilt the dishwasher back carefully or lay it on its side
3. Locate the pump motor and disconnect its wiring connector
4. Test resistance across pump terminals with a multimeter — expect approximately 20–40 ohms
5. Open circuit (OL) indicates a failed pump motor winding — replace the pump

Step 7: Reset and Verify

1. Reconnect all components and restore power
2. Run a short rinse cycle or a diagnostic drain cycle
3. Listen for the pump activating and water flowing into the drain
4. If E24 clears and the dishwasher drains normally, the repair is complete
5. If E24 persists after all steps, the control module may need professional diagnosis

When to Call a Professional

Most E24 error resolutions are DIY-friendly since they involve external hose inspection and filter cleaning. However, professional service is recommended in these situations:

• Drain pump replacement needed — Accessing the pump requires tilting or laying the dishwasher on its side and working in a tight space with electrical connections
• Integrated installation complications — If your Bosch dishwasher is panel-ready and fully integrated into custom cabinetry, pulling it out for hose inspection may risk damage
• Repeated E24 after clearing all blockages — This may indicate a control board issue or intermittent pump failure that requires diagnostic equipment
• Water damage present — If E24 coincides with water leaking under or around the dishwasher

Average Repair Costs: Professional drain hose service runs $100–$175 (diagnosis + fix). Drain pump replacement costs $175–$300 (parts + labor). Control board replacement ranges from $300–$500 installed. A Bosch-authorized technician is recommended for warranty claims. 125

Preventing Future E24 Errors

Proactive maintenance significantly reduces the likelihood of drain blockage issues on Bosch dishwashers:

Weekly Maintenance

• Scrape all plates thoroughly before loading — Bosch says "no pre-rinse needed" but large food debris should be removed
• Run the garbage disposal before starting the dishwasher to clear the shared drain path
• Check the drain filter for visible debris accumulation and rinse if needed

Monthly Maintenance

• Remove and deep-clean the triple filter system (coarse filter, fine mesh, and housing)
• Inspect under the sink for anything pressing against or kinking the drain hose
• Run an empty hot cycle with a dishwasher cleaner or 2 cups of white vinegar placed in a bowl on the top rack

Annual Maintenance

• Pull the dishwasher forward to inspect the full drain hose run for deterioration
• Verify the high loop is still secured at the highest point under the counter
• Check hose clamps at both connection points for tightness
• Inspect the pump area (with filters removed) for accumulated grease or small debris

Installation Best Practices

• Always install with a high loop or air gap — this is required by Bosch and most plumbing codes
• Keep the drain hose length under 10 feet total (Bosch specification)
• Avoid routing the hose through tight spaces where kinking is likely
• After garbage disposal replacement, always verify the knockout plug is removed

Bosch Dishwasher Models Commonly Affected by E24 Error

The E24 error code can appear on any Bosch dishwasher model that uses the electronic drain monitoring system. Here are the most frequently reported models and their key replacement part numbers:

Model NumberSeriesDrain Pump PartFine Mesh Filter
SHP65TL5UC500 Series0062077400645038
SHPM88Z75N800 Series0062077400645038
SHE68TL5UC800 Series0062077400645038
SMS46GI01ASerie 40062077400645038

All current Bosch dishwasher models share the same drain pump platform (00620774) and filter system (00645038), making parts interchangeable across the 300, 500, 800, and Benchmark series. When ordering replacement parts, verify your model number on the rating plate located on the left side of the door opening.

Note on E24 vs. E25: If your Bosch model is from 2018 or later, Bosch updated their diagnostic firmware. Some newer models display E25 for pump cover issues that older firmware would have reported as E24. If you see E25, focus specifically on the pump impeller cover and check valve rather than the external drain hose. 127