E1 on a Thermador CT/CMT Wall Oven with Dreefs Control: Control Board Problem

What E1 means

E1 appears in the oven or selector window on legacy Thermador CT and CMT built-in ovens (convection and convection-microwave) that use the Dreefs control. The control has flagged a problem with its own board, so it switches off the CLEAN cycle in both ovens while COOK and the microwave still work. Turning the oven off stops the message, and it comes back only when the selector is turned to CLEAN. Power must be cycled off and on to clear it.

Usual causes of E1

Control board problem, which is how the service table words E1
Selector switch or latch switch wiring that confuses the board (the same table names these parts for neighboring codes)
Temperature sensor input read incorrectly by the control

✓ A safe check worth trying

1. Turn the selector knob to OFF, then nudge it slightly counterclockwise to stop any flashing or beeping. 2. Cut power to the oven for a moment at its breaker and restore it. 3. Use COOK normally and leave CLEAN alone. 4. If E1 returns the next time you select CLEAN, write down that detail and call us. Do not open the control panel.

! Why you should stop here

The control board and selector wiring sit behind live panels in a built-in oven
Replacing a board without confirming the cause can leave the same message on screen
Older Dreefs units need the model number checked before we quote, and we quote in writing first

Taking off a panel yourself does not by default void a manufacturer warranty, yet it can lead to accidental damage, and some manufacturers attach their own service terms. Read your warranty paperwork, or ask us, before you decide.

→Same appliance

More Oven codes

E15Thermador Legacy Oven, Dreefs Control Code E15: Board Replacement on CT/CMT Models F33Thermador Older C-Series Upper Oven F33, Over Temperature While Cooking F82Legacy Thermador Wall Oven, C/CM Series, Shows F82: Lower Door Reads Locked and Open E...Thermador Steam and Convection Oven E... Messages on Legacy MES301HS and MES301HP F10Thermador C-Series Wall Oven F10 on C/CM/CJ Models: Power Board Incompatibility F34Thermador Legacy C/CM/CJ Oven F34: Upper Oven Cooling Fan Air Switch Not Detected F83Reading F83 on Older Thermador C/CM Wall Ovens (Lower Door Stuck Position) ErrThermador POD Built-In Oven Err on Legacy POD301, POD302, PODC302, PODM301 and PODMW301: Invalid Temperature

E1E1 questions

Can I keep baking while E1 is showing?

The source says COOK and the microwave stay available while CLEAN is disabled. Avoid self-clean until the control is checked, because that is the only mode that brings the message back.

Why does E1 only return when I pick CLEAN?

After a power cycle the control stays quiet until the selector reaches CLEAN, which is the mode it has blocked. That pattern tells us the board is still flagging itself even though normal baking looks fine.

Is E1 the same on a newer Thermador wall oven?

No. Newer Thermador ovens use different code tables, and the same symbol can mean something else. This page covers only legacy CT and CMT ovens with the Dreefs control, and we confirm the model on site.