Bosch Washer Error Codes — Complete E-Code Guide & Fixes

Bosch compact front-loaders use the E:XX error code format to communicate specific faults to the user. Unlike generic appliance error codes that require cross-referencing a manual, Bosch codes follow a logical system: water-related faults start in the E:0X and E:1X range, motor and mechanical faults in E:2X, and sensor/electronic faults in E:3X and above. Understanding this system lets you diagnose most problems without opening the machine.

Bosch washers in the 300, 500, and 800 series (model prefixes WAT, WAW, WGA) share the same core error code system, though 800 series models with Home Connect WiFi provide additional detail through the smartphone app. On 300 series models with basic LED displays, the error shows as a blinking pattern that corresponds to the E number.

How to Read Bosch Error Codes

When an error occurs:

1. The current cycle pauses or aborts.
2. The display shows "E:" followed by a two-digit number.
3. The code remains visible until you rotate the program selector to OFF or unplug the machine.
4. On 800 series with Home Connect, the error also appears in the app with a brief description.

Important: Write down the code before turning off the machine. Some codes are only displayed once and require entering diagnostic mode to retrieve the error log.

Water Supply Errors

E:02 — Water Inlet Fault

Meaning: The machine is not receiving water or receiving it too slowly.

Common causes on Bosch compact washers:

• Supply valves closed (check both hot and cold)
• AquaStop hose triggered (red indicator in the transparent window on the hose connector)
• Inlet valve filter screens clogged with Sacramento hard water mineral deposits
• Inlet valve solenoid failure (BSH 00622058 — dual solenoid on Bosch models)
• Water pressure below 20 PSI minimum

Fix:

1. Check that both supply valves are fully open.
2. Inspect the AquaStop hose — if the red indicator is visible, the hose must be replaced entirely (it cannot be reset).
3. Disconnect the supply hoses from the back of the machine and check the inlet filter screens (fine mesh at the valve entry). Clean with an old toothbrush and vinegar to dissolve calcium.
4. If screens are clear and water pressure is adequate, the inlet valve solenoid likely needs replacement.

Parts: $35–$75 (inlet valve) | Professional repair: $120–$250

E:04 — General Drain Fault (Older Models)

Meaning: The drain cycle did not complete successfully. On newer models, this is split into E:18 and E:29 for more specificity.

Fix: Same procedure as E:18 below.

E:17 — Water Fill Timeout

Meaning: Water entered the machine but did not reach the required level within the expected time.

Common causes: Partially clogged inlet screens, low municipal pressure, or a kinked supply hose behind the machine in a tight laundry closet.

Drain Errors

E:18 — Drain Time Exceeded

Meaning: The drain pump ran but water level did not drop to empty within the allowed time window (typically 3–5 minutes).

This is the single most common Bosch error code. In our Sacramento service experience, approximately 45% of Bosch washer service calls involve E:18.

Fix:

1. Open the service flap (bottom-left front).
2. Pull out the emergency drain hose and evacuate water into a container.
3. Unscrew the drain filter cap counterclockwise. Remove debris (coins, lint, hair clips, underwires).
4. Check pump impeller — spin with finger to confirm free rotation.
5. Inspect the external drain hose for kinks, especially at the anti-siphon loop.
6. If the filter is clear and the pump spins freely but E:18 persists, the pump motor (BSH 00145787) may be weak or the sump hose internally restricted.

Parts: $0 (filter cleaning) or $55–$110 (pump replacement) | Professional repair: $80–$280

E:29 — Drain Fully Blocked

Meaning: The pump detected zero water flow. More severe than E:18 — indicates a complete obstruction rather than a restriction.

Fix: Same procedure as E:18, but focus on complete blockages: a sock or cloth item fully blocking the pump inlet, or the drain hose detached from the standpipe.

Motor and Mechanical Errors

E:21 — Motor / Inverter Communication Fault

Meaning: The main control board cannot communicate with the EcoSilence Drive motor's inverter module, or the inverter reports an internal fault.

Common causes:

• Inverter module MOSFET failure (power surge damage)
• Loose 6-pin connector between motor and main board (vibration-induced)
• Motor winding fault (rare on brushless EcoSilence Drive)

Fix:

1. Remove the rear panel (6x Torx T20).
2. Check the 6-pin connector at the motor inverter module — reseat firmly.
3. Inspect the inverter module for burn marks or melted plastic.
4. If connector is secure and no visible damage, the inverter module likely needs replacement.

Parts: $120–$250 (inverter module) | Professional repair: $250–$450

E:23 — AquaShield / Leak Detection Activated

Meaning: The float sensor in the base pan detected water — an internal leak has occurred.

Common causes:

• Door boot gasket tear (leak during spin pushes water into the base pan)
• Drain pump housing seal failure
• Detergent dispenser-to-tub hose disconnection
• Tub-to-pump sump hose crack

Fix:

1. Do NOT simply reset and run another cycle. The machine detected a real leak.
2. Tilt the machine backward slightly and check for water in the base pan.
3. Mop out the base pan and run a short cycle while observing for the leak source.
4. Common locations: front door gasket area, pump housing underneath, and left-side dispenser channel.

Parts: Varies by leak source | Professional repair: $150–$450

E:25 — Pressure Sensor / Turbidity Sensor Fault

Meaning: The water level or water clarity sensor is not providing expected readings.

Fix: Check the pressure sensor hose (thin rubber tube running from the right side of the frame to the tub bottom) for disconnection, kinks, or detergent residue blocking the tube. Blow through gently to clear.

Temperature and Heating Errors

E:05 — NTC Temperature Sensor Fault

Meaning: The NTC thermistor is reading out of range (open circuit or short circuit).

Fix: Access the NTC from the rear panel — it is located in the heating element housing at the lower tub. Test with a multimeter: should read approximately 10-15K ohms at room temperature, decreasing as temperature rises. Replace if open or shorted.

Parts: $30–$60 | Professional repair: $120–$220

E:06 — Heating Element Fault

Meaning: The heating element is not producing heat or has an electrical fault.

Fix: Test the heating element for continuity (should read 20–30 ohms). Also test for earth leakage between element terminals and ground. Replace if open circuit or leaking to earth.

Parts: $60–$130 | Professional repair: $150–$300

Entering Diagnostic Mode for Error History

Bosch washers store the last several error codes in memory. To retrieve them:

1. Turn the program selector to OFF.
2. Press and hold Start, then rotate selector to Permanent Press.
3. Release Start when the display activates.
4. The most recent error code displays immediately.
5. On some models, pressing the RPM button cycles through stored error history.

Error Codes That Require Immediate Professional Service

• E:23 with visible water on the floor — Active internal leak, risk of electrical damage
• E:21 with burning smell — Motor inverter failure with thermal damage
• Any E code accompanied by tripped circuit breaker — Potential short circuit
• E:57 or higher — Board-level faults requiring Bosch service tool for diagnosis

Clearing Error Codes

Most Bosch error codes clear automatically when the fault is resolved and a new cycle completes successfully. To force-clear:

1. Unplug the machine for 5 minutes.
2. Reconnect and run a quick Rinse/Spin cycle.
3. If the error does not reappear, the fault was transient.
4. If it returns, the underlying cause persists and requires repair.

Prevention

• Clean the drain filter every 2–4 weeks to prevent E:18/E:29 (the most common codes).
• Install a surge protector to prevent E:21 motor inverter damage from power fluctuations.
• Use correct HE detergent amounts — oversudsing triggers extended cycles and can cause E:23 through dispenser overflow.
• Inspect AquaStop hose annually — a triggered hose causes E:02 that looks like a valve failure.

FAQ

Q: My Bosch washer shows E:18 after every wash. Is the pump dead?

Not necessarily. Persistent E:18 with a clean filter usually means the pump is weakening or the sump hose is partially restricted. Try cleaning the internal sump hose before replacing the pump.

Q: Can I ignore a Bosch error code if the cycle finishes?

Some codes are warnings that allow cycle completion (like oversuds). Others (E:23, E:21) indicate active damage. Never ignore E:23 — it means water is where it should not be.

Q: My Bosch washer shows an error code then clears itself. Should I worry?

A single occurrence may be transient (power fluctuation, temporary low water pressure). If the same code recurs within a week, the underlying cause is developing and will worsen.

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