Bosch Dryer E12 Means It Overheated From Blocked Airflow

What E12 means

Clothes come out hot but still damp, or the dryer shuts down mid-cycle, and E12 appears. The machine measured heat building up faster than the air could carry it away, and stopped itself. Nearly every time the reason is airflow: a lint screen packed with fluff, or a vent line that is blocked, bent or too long, leaving the hot, humid air with nowhere to go.

Common causes of E12

Lint screen coated or full of lint (the first place to look)
Exhaust vent that is blocked, crushed or longer than it should be
Debris or a bird nest in the outside vent opening

✓ One safe check you can try

1. Turn the dryer off and let the drum cool before touching anything. 2. Pull out the lint screen and clean it completely. 3. Go outside and check that the vent flap swings open freely and is not bent, crushed or stuffed with debris. 4. Run a short cycle. If E12 returns, the blockage is farther down the duct. Do not keep trying; call us.

! Why to stop there

Restricted dryer airflow is a real fire hazard, so resetting the code without clearing the blockage leaves the danger in place.
Reaching into the duct while the dryer is still plugged in means working near a live heating element.
A duct cleared only partway can leave lint packed farther along, which catches more easily than a vent that is simply blocked.
Putting the duct back with gaps can push hot, wet air into the wall cavity instead of outdoors.

Opening a panel yourself does not automatically cancel a manufacturer warranty, but it can cause accidental damage, and some manufacturers set their own service conditions. Check your warranty terms, or ask us, before deciding.

→Same appliance

Other Dryer codes

E:03Bosch Dryer E:03 Appears When Laundry Will Not Get Dry Enough E:11Bosch Dryer E:11 Is a Quiet Early Warning About Airflow E:15Bosch Dryer E:15 Means the Heating Circuit Is Not Working E:17Bosch Dryer E:17 Reports the Exhaust Air Sensor Is Off E:18Bosch Dryer E:18 Flags the Sensor Above the Heater E24Bosch Dryer E24 Means the Self-Check Found an Electronics Error E10Bosch Dryer E10 Points to the Control Module or Its Wiring E52Bosch Dryer E52 Signals a Problem With the NTC Temperature Sensor

E12E12 questions

I emptied the lint screen and E12 is still there. What now?

That points to a blockage deeper in the vent run. Long runs especially tend to need a professional duct cleaning or inspection with the right equipment.

Is E12 something to take seriously?

Yes, absolutely. A restricted vent is a recognized cause of dryer fires, so treat this code as a priority and not as a nuisance message.

How long does clearing a vent usually take?

It depends on the length and layout of the run. We look at it first, give you a written price, and you approve it with us before any work starts.