Bosch Dryer E12 — Airflow Restriction / Vent Blockage (Vented Models)
Bosch Dryer · Error code E12
What E12 Means
On vented dryers, control detects insufficient airflow through the system — typically a blocked exhaust vent. Will cause long cycles and overheating.
Symptoms
- Cycle takes much longer than normal
- Clothes hot but still damp
- Dryer cabinet hot to touch
- Lint accumulating around door seal
Common Causes
Bird nest, lint buildup, or closed louvers at exterior wall vent.
Foil/plastic transition hose pinched behind dryer.
Long vent runs accumulate lint over years and need professional cleaning.
Combustible flexible duct should be replaced with smooth-wall rigid metal.
Code limit typically 25 feet minus 5 feet per 90-degree elbow.
How to Fix It
- Disconnect the transition duct at the back of the dryer.
- Run a short test cycle — if E12 clears, the restriction is downstream.
- Inspect the transition duct from dryer to wall — replace with smooth rigid metal if it's foil or plastic.
- Inspect the exterior vent hood — clean out lint, leaves, and any nests; verify the damper flap moves freely.
- Have the vent run professionally cleaned if it exceeds 10 feet or has multiple elbows.
- Measure vent run length and elbow count; reroute if it exceeds code limits.
- Reconnect transition duct, ensuring no kinks, and run a full cycle to verify normal drying time.
Parts You May Need
If diagnosis points to a failed part, these are the common replacements. As an Amazon Associate we earn from qualifying purchases.
More Bosch Dryer Codes
Verified against manufacturer documentation: bosch-home.com
Always unplug an appliance before servicing it. This guide is for informational purposes and is not a substitute for a qualified technician.