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
- 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.
- 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.
- Inspect visible wiring and connectors: Unplug the washer and inspect wiring to the heater and temperature sensor for burns, corrosion, or loose connectors.
- 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.
- Test the heating element: With power disconnected, measure element continuity. An open element or very low/high resistance indicates a fault.
- Check thermal fuse/thermostat: Test for continuity on any thermal cut-outs or fuses located near the heater. Replace if open.
- Look for signs of water damage: