Code: E12🌀 Bosch Dryer

Bosch Dryer E12 Error Code: Overheating From Restricted Airflow

Reviewed 2026-10-26 · Based on 3 manufacturer & service sources

What the code means

Bosch's dedicated US help page for dryer E12 says the code indicates overheating due to restricted airflow. The service manual for the Bosch WTMC8330US condenser dryer, as quoted by the technician reference MyPros+, is more precise: E:12 is overheating (fluffing) level 2, set when the heater temperature rose more than 7 degrees C within 5 seconds, 10 times, and the listed causes are a blocked fluff (lint) filter, container or air routes. In plain terms, lint is choking the airflow, the heater gets hot too fast, and the control stops the cycle to protect the dryer. One heading on Bosch's US error code list says E12 is limescale build-up in the heat pump, but the explanation under it and Bosch's own E12 page both describe overheating from restricted airflow (the limescale wording matches Bosch's dishwasher E12 page), so treat airflow as the thing to check. Because the 7-degree detail comes from one model's service manual, other Bosch models may set E12 slightly differently.

Likely causes

Safe DIY checks

⚠ Before you start

Unplug the appliance or switch off its breaker before opening panels.

  1. Turn the dryer off and unplug it, then note the exact code and your model number (E-Nr) from the rating label inside the door.
  2. Pull out the lint screen, clear the lint off it, and wash it in warm soapy water if it looks clogged. Let it dry completely before putting it back. Bosch also says to remove any lint left in the slot the screen fits into.
  3. Vented models: pull the dryer away from the wall, disconnect the duct and clean it with a dryer vent brush or a vacuum attachment. Replace a crushed or kinked duct, then check that the outside vent hood opens freely and isn't blocked.
  4. Condenser models: clean every filter your manual lists (many Bosch condenser dryers have a second filter in front of the condenser) and wipe lint off the openings around the condensate container. Rinse the condenser itself if your manual says it's removable.
  5. Power reset: leave the dryer unplugged or the breaker off for at least 5 minutes, plug it back in and run a test cycle with a small load.
  6. If E12 comes back with clean filters and a clear vent, stop there. Don't take the cabinet apart or bypass any thermal protection.

🛠 When to call a pro

  • E12 keeps returning after the lint screen, filters and vent are clean: call Bosch Customer Support at 1-800-944-2904 (US) or book an authorized technician, and give them your E-Nr.
  • Tell them it's an overheating code, so they check the internal air path, blower and heater temperature sensing rather than just clearing the code.
  • The dryer smells hot or burnt, or the cabinet gets very hot: unplug it and don't use it until it's been inspected, because lint build-up is a fire risk.

Parts that commonly fix it

Always match the part number to your exact model.

⚙

Dryer vent cleaning brush kit

For clearing lint out of the duct and the lint screen housing.

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⚙

Lint filter

Only if yours is torn or warped. Match the filter to your Bosch E-Nr.

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⚙

Rigid metal dryer duct

To replace a crushed or kinked foil duct on vented models.

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Sources

  1. Bosch US: How To Fix Bosch Dryer Error Code E12 (overheating due to restricted airflow; clean lint screen and housing, clear external vent and duct, test cycle; 1-800-944-2904)
  2. Bosch US: Dryer Error Codes guide (E12 entry: dryer overheating, potentially due to restricted airflow; power cycle reset for at least 5 minutes)
  3. MyPros+: Bosch Dryer Error Code E:12, quoting the Bosch WTMC8330US service manual p. 21, 24 (overheating level 2: heater temperature rose more than 7 C in 5 seconds 10 times; fluff filter, container or air routes blocked)

Last reviewed 2026-10-26. Always confirm against the manual for your exact model number.