Code: E20🌀 Bosch Dryer

Bosch Dryer E20 Error Code: Control Module Memory or Software Fault

Reviewed 2026-10-26 · Based on 4 manufacturer & service sources

What the code means

Bosch's public dryer error code guide doesn't list E20 by itself, so the meaning comes from Bosch service documentation for the US WTMC dryers. The fault table reproduced on Appliantology from Bosch's WTMC service material lists E:20 as an EEPROM error, with the solution 'replace faulty control module' and the effect that the dryer stops and can't be restarted. The neighbouring codes E:21 to E:26 in the same table are also control module faults (checksum, invalid update, model variant, software version, data table). MyPros+, quoting the Bosch WTMC8330US service manual p. 21, describes E:20 as control fault 1 (update invalid): the process software was set or programmed incorrectly. Both point to the same thing: the dryer's control electronics can't read or trust their own software or settings. That's why a lint, vent or hose fix won't clear it, and why the repair is board-level. Bosch's US guide says its other electronic fault codes (E06, E08, E09, E24, E25, E28, E36, E90) need an authorized technician, and the same applies here. Note that on a Bosch washing machine, E20 or F20 means something different: Bosch says it indicates unexpected heating. See also the related Bosch dryer pages for E24 and E90.

Likely causes

Safe DIY checks

⚠ Before you start

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

  1. Write down the exact code and your model number (E-Nr) from the rating label inside the door.
  2. Power reset: unplug the dryer or switch off its breaker for at least 5 minutes, then power it back on and try a short program.
  3. If the control board was replaced or reprogrammed recently, tell the technician who did it, since an invalid update can show as E20.
  4. If E20 returns, stop there. Bosch's service table says the dryer stops and can't be restarted, and the fix is the control module.

🛠 When to call a pro

  • E20 comes back after a power reset: call Bosch Customer Support at 1-800-944-2904 (US) or book an authorized technician, and give them your E-Nr.
  • Ask them to confirm the code in service test mode and check whether the control module can be reprogrammed before replacing it.
  • If a new control module is fitted, it must match your dryer's E-Nr and be programmed correctly, or a control fault code can return.

Parts that commonly fix it

Always match the part number to your exact model.

⚙

Dryer main control board

Bosch's service table lists replacing the control module as the fix. Match the part to your Bosch E-Nr.

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⚙

Digital multimeter

For a technician checking supply voltage and wiring before condemning the board.

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Sources

  1. Appliantology: Bosch WTMC dryer service test mode and fault table (E:20 EEPROM error; replace faulty control module; dryer stops and can't be restarted)
  2. MyPros+: Bosch Dryer Error Code E:20, quoting the Bosch WTMC8330US service manual p. 21 (control fault 1, update invalid: process software set or programmed incorrectly)
  3. Bosch US: Dryer Error Codes guide (electronic fault codes need an authorized technician; 1-800-944-2904)
  4. Bosch US: Washing machine error code E20 or F20 (on washers it means unexpected heating, a different fault)

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