Bosch Washer Error Code E29

What the Bosch Washer Error Code E29 Means

Error code E29 on a Bosch front-load washer typically indicates a fault in the heating circuit or the washer’s temperature-sensing system (an NTC thermistor / temperature sensor issue) or a related control/communication problem. When the washer detects an unexpected temperature reading, a failed heater, or a short/open in the heating circuitry it will stop the program and display E29 to protect the appliance and your home.

Why it occurs: common triggers include a failed temperature sensor (NTC), an open or shorted heating element, a blown thermal fuse or thermostat, damaged wiring between the sensor/heater and the control board, or a malfunctioning electronic control/PCB. External factors — like mineral buildup on the heater, repeated overheating, or water intrusion into electrical components — can also lead to this error.

User impacts: E29 can cause longer wash cycles (the machine may try to re-run temperature checks), incomplete or cold washes, laundry that isn’t properly sanitized, higher energy consumption, and in rare cases safety risks such as overheating or electrical faults. It can also leave the washer in an error-locked state so no programs will run until the fault is cleared.

Common Causes

• Faulty NTC temperature sensor (incorrect or no temperature reading)
• Failed heating element (open circuit or short)
• Damaged wiring harness or connector to heater/sensor
• Malfunctioning control board / PCB (faulty relay or sensor input)
• Blown thermal fuse or tripped thermostat/thermal cut-out
• Water ingress or corrosion on electrical components
• Scale or limescale accumulation on the heater causing overheating/failure

Troubleshooting Steps

1. Power cycle the washer: Turn off and unplug the machine for 5–10 minutes, then plug in and try a short program to see if the error reappears. This clears transient errors.
2. Check error memory: If your model allows, read diagnostics from the control panel or use Bosch’s service mode to confirm E29 and any related codes.
3. Inspect visible wiring and connectors: Unplug the washer and inspect wiring to the heater and temperature sensor for burns, corrosion, or loose connectors.
4. Test the NTC temperature sensor: With the washer unplugged, locate the sensor and measure its resistance with a multimeter at room temperature (typically 10–30 kΩ depending on model). Compare to Bosch specs or service literature.
5. Test the heating element: With power disconnected, measure element continuity. An open element or very low/high resistance indicates a fault.
6. Check thermal fuse/thermostat: Test for continuity on any thermal cut-outs or fuses located near the heater. Replace if open.
7. Look for signs of water damage: Inspect the control board area for corrosion or water traces. Water on PCB or connectors can cause intermittent E29 errors.
8. Remove limescale build-up: If the heater shows heavy scale, descale according to Bosch guidance or replace the element if damaged.
9. Swap or inspect the control board: If sensors and heater check out, the control board (sensor input circuit or relay) may be at fault — this step usually requires a qualified technician.
10. Reset and test: After repairs or replacements, reset the washer and run a complete cycle with a small load to verify the error is cleared and the heater functions normally.

Maintenance / Prevention Tips

• Run a monthly appliance care or maintenance wash (empty) with a Bosch-approved cleaner to reduce residue build-up.
• Use water softeners or descaling agents if you live in a hard-water area to prevent limescale on the heater.
• Avoid overloading the washer — heavy loads put extra strain on components and can cause prolonged heating cycles.
• Use the recommended detergent and follow dosage instructions to reduce residue on internal parts.
• Periodically inspect power and supply hoses for leaks that could reach electrical parts.
• Keep the washer area dry and well-ventilated to reduce humidity and corrosion risk.
• Have the washer serviced every 1–3 years, especially if used heavily or in commercial settings.
• Replace aging wiring harnesses or connectors that show wear before they fail.
• Promptly address other error codes (e.g., drainage or inlet errors) — unresolved issues can lead to secondary faults like E29.
• When descaling, follow Bosch guidance to avoid damaging seals or electronics.
• Use manufacturer-approved replacement parts when repairing heaters, sensors, or PCBs.
• Keep the machine’s firmware updated if updates are provided by Bosch or a service technician.
• Limit use of high-temperature programs unless necessary to reduce heater cycling.
• Secure the washer to reduce vibration that can loosen connectors over time.
• Keep receipts and service records — recurring E29 events may indicate a component near end-of-life.

FAQs

Conclusion / Safety Notice

Because E29 usually involves the washer’s heating circuit or temperature-sensing components, there are electrical and thermal safety considerations. Always disconnect power before inspecting or replacing electrical components. If you see signs of burnt wiring, water-damaged electronics, or repeated errors after basic checks, stop further troubleshooting and contact a certified Bosch technician.

For safety and best results: attempt only basic steps (power cycle, visual inspection) unless you are comfortable with electrical testing and appliance repair. When in doubt, schedule professional service to diagnose and repair E29 to protect your washer and home.