Bosch · Dryer
Bosch Dryer E09 Error Code
Heat pump or element regulation fault
What this error means
E09 on Bosch heat-pump dryers indicates an electronic fault in the heat regulation path—grouped with E06 and E08 on the official chart. Heat output stops even though the drum may continue tumbling on some firmware versions.
How E09 is detected
When E09 appears on a Bosch dryer, the control board has confirmed that water did not leave the machine within the programmed drain window. On Bosch WQB245AXUC, Bosch WTG865H4UC, 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 E09 calls are resolved without parts: clean lint filter, condenser, and drain hose before any retry. 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 E09 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
- Heat pump module communication loss after condenser overheating
- Refrigerant circuit fault on sealed heat-pump systems
- Board relay failure preventing compressor or element activation
- Thermal cutoff opened from prior lint blockage
Step-by-step fixes
- 1Clean lint filter, condenser, and drain hose before any retry
- 2Reset breaker thirty seconds per Bosch guidance
- 3Run a timed cycle on low heat to test—avoid high heat until E09 clears
- 4Record whether the exhaust air ever warms during the test cycle
When to call a technician
Recurring E09 after full maintenance cleaning requires heat-pump module or board service—refrigerant work is sealed-system only.
Affected models
- Bosch WQB245AXUC
- Bosch WTG865H4UC
- Bosch WTG86401UC
Prevention & maintenance
- Clean drain filters and hose terminations monthly on high-use dryers to prevent E09 from lint and food debris buildup.
- Record when E09 appears in the cycle and whether it clears after a 60-second power reset on your Bosch dryer—that detail speeds diagnosis if you call service.
- Keep the model and serial number from the rating plate when ordering parts for E09; Bosch uses multiple revisions with different harness lengths and board firmware.
- Photograph wiring connector orientation before disconnecting any component while troubleshooting E09; reversed plugs on pumps and valves cause immediate repeat faults.