Bosch · Dishwasher
Bosch Dishwasher E08 Error Code
Heat exchanger or turbidity sensor fault
What this error means
E08 on select Bosch dishwashers flags a heat exchanger or water-quality sensor fault—the internal heat exchanger that preheats inlet water sent readings outside range. Often appears in hard-water areas after months without descaling.
How E08 is detected
When E08 appears on a Bosch dishwasher, the control board has confirmed that water did not leave the machine within the programmed drain window. On Bosch SHPM65Z55N, Bosch SHEM63W55N, and similar variants, the drain pump runs for a fixed interval—often three to seven minutes on washers and dishwashers—while a pressure switch or turbidity sensor verifies the tub or sump is empty. If water remains, the cycle stops to prevent spin with a full tub or overflow on the next fill.
Most E08 calls are resolved without parts: run an empty cycle with bosch descaler at the hottest available temperature. Restricted drain paths mimic pump failure because the impeller spins against a blocked hose or filter. Document whether the pump hums audibly during the drain step; a humming pump with no water movement points to a clogged filter or kinked hose, while silence may indicate a failed pump motor or loose wiring at the harness.
After clearing blockages, run a short cycle and listen at the drain hose for steady water flow. If E08 returns on the next load with a clean filter and straight hose, measure resistance at the pump motor connector per the service manual for your model before ordering a replacement pump assembly.
Common causes
- Limescale insulating the heat exchanger passages
- Turbidity or conductivity sensor coated with mineral film
- Heat exchanger thermistor open circuit
- Inlet water colder than design minimum for sensor calibration
Step-by-step fixes
- 1Run an empty cycle with Bosch descaler at the hottest available temperature
- 2Fill the salt reservoir if your model has a water softener function
- 3Reset breaker thirty seconds after descaling completes
- 4Use rinse aid and softening salt regularly in hard-water regions
When to call a technician
E08 returning within a week after descaling suggests heat exchanger sensor or module replacement.
Affected models
- Bosch SHPM65Z55N
- Bosch SHEM63W55N
- Bosch SHX5AVF5UC
Prevention & maintenance
- Clean drain filters and hose terminations monthly on high-use dishwashers to prevent E08 from lint and food debris buildup.
- Record when E08 appears in the cycle and whether it clears after a 60-second power reset on your Bosch dishwasher—that detail speeds diagnosis if you call service.
- Keep the model and serial number from the rating plate when ordering parts for E08; Bosch uses multiple revisions with different harness lengths and board firmware.
- Photograph wiring connector orientation before disconnecting any component while troubleshooting E08; reversed plugs on pumps and valves cause immediate repeat faults.