Bosch Dishwasher Error Code E08 — Meaning, Causes & Fixes
What E08 means: On many Bosch dishwashers, the error code E08 indicates a heating-related fault. The appliance is reporting that water temperature did not rise as expected during the cycle or that the control electronics are detecting a fault in the heating circuit. This can be caused by a failed heating element, a defective temperature (NTC) sensor, a bad heating relay/triac on the main control board, wiring/connectors that are corroded or open, or a safety component such as a thermal fuse.
Why it occurs and how it impacts you: When the dishwasher cannot reach or measure the proper wash temperature the unit may lengthen cycles, fail to complete on schedule, perform poor cleaning or drying, and be unable to run high-temperature sanitizing programs. In some cases the dishwasher will lock the cycle and display E08 until the fault is addressed. There are safety and appliance longevity concerns: a shorted heating element or damaged wiring can create an electrical hazard, while a non-heating dishwasher may not sanitize dishes properly and can lead to persistent odors and increased energy use as the control tries repeatedly to heat water.
Common Causes
- Failed heating element (open or shorted)
- Defective temperature sensor (NTC thermistor) or poor sensor connection
- Bad relay or triac on the main control board that switches the heater
- Burnt or damaged control board electronics
- Wiring harness issues: loose, corroded, or broken connectors
- Tripped thermal fuse or other safety cut-out
- Low incoming water temperature or incorrect water supply
- Severe scale build-up on the heater causing reduced heat transfer
Troubleshooting Steps
- Safety first: disconnect the dishwasher from power (turn off the breaker) before inspecting electrical components. Do not attempt live testing unless you are qualified.
- Power-cycle the appliance: switch power off for 1–2 minutes and then back on. Sometimes an intermittent error clears and reveals if it was a transient glitch.
- Run a diagnostics/service mode if your model supports it to capture the heater/NTC readings and see if the code reappears. Consult your Bosch service manual for the exact sequence to enter diagnostics.
- Check water supply: ensure hot water enters the machine (hot tap) and that the incoming water temperature is adequate for the selected program. Cold feed can make the controller think heating failed.
- Inspect visible wiring and connectors around the heater and control board for burned insulation, corrosion, or loose pins. Repair any damaged connectors before further testing.
- Measure the heating element for continuity with a multimeter. An open element usuall