An E01 code means the main control board has suffered an internal hardware failure. While you can try a hard power reset to clear a temporary glitch, this code usually requires replacing the power module located at the base of the unit.
Ignore this code and you're not getting a second warning. The board already decided it can't safely run the heater circuit and it's just sitting there waiting. In most cases I show up and find a module that got fried by a surge or cooked itself from years of heat cycling in a tight base cabinet. Fix it soon or you'll be shopping for a new unit instead of a new board.
OK so here's the deal with E01: it's a board-level failure, full stop. Not your drain filter, not the spray arms, nothing you can clean or unclog. The control module ran its self-check and found something wrong internally, usually in the power stage that drives the heater. These Thermador boards aren't cheap, which is why I always try a reset first, but honestly if the code comes back you're looking at parts and probably a tech.
Most Likely Causes
Based on aggregated repair data, here is the probability breakdown for this error code:
Main Power Module Failure85%
Wiring Harness Issues10%
External Power Supply Fault5%
Symptoms You May Notice
Dishwasher stops dead mid-cycle, door still locked, water still sitting inside.
E01 flashes on the display and the unit won't respond to any button you press.
A faint burnt plastic smell coming from the bottom of the unit near the kick plate.
Control panel goes completely dark or unresponsive, like there's no power at all even though the breaker's on.
Unit starts a cycle, runs for a few minutes, then cuts out and throws the code.
Can you reset a Thermador dishwasher to clear the E01 code?
Flip the dishwasher's circuit breaker off and leave it for a full 10 minutes. If it's plugged directly into an outlet, unplug it instead. After restoring power, press and hold the Start button for 3 to 5 seconds. The display should clear. If E01 shows back up within the first cycle, the hardware is genuinely failed and no reset is going to fix it. At that point you're looking at a new power module.
Tools Required for Diagnosis
Torx T20 screwdriverPhillips #2 screwdriverDigital multimeterNeedle-nose pliersFlashlight or headlampNut driver set (1/4 inch and 5/16 inch)
Diagnostic Checklist
Follow these steps in order. We start with the easiest external fixes before opening up the machine.
ComponentComponent Under Test
Expected Range15–30 ohms
ConditionIf Open (OL) or infinite, replace component.
Frequently Asked Questions
Can I fix a Thermador E01 error without replacing parts?
Honestly, sometimes yes. If a power surge tripped something temporarily, a full 10-minute breaker reset clears it and you never see it again. I've had that happen a handful of times. But if the code comes right back after the reset, you're not going to talk your way out of a parts replacement. The internal circuitry on that module is gone and there's nothing to reset your way past it.
How much does it cost to fix an E01 error?
Budget for the part alone being $250 to $450 depending on your model. The DWHD650WFM and the higher-end panel-ready models tend to run toward the top of that range. If you're calling a tech, add $150 to $250 for labor and a trip charge. So yeah, you could be looking at $500 to $700 all in. That's why I always tell people to do the reset first and confirm the board is actually dead before ordering anything.
Is the E01 code the same as the E09 code?
No, they're different problems. E09 means the heating element itself is open or failed, which is actually a cheaper fix, usually just a heater swap. E01 is worse because it means the control board's power stage that drives that heater has failed internally. The board is the expensive part. And here's the thing, if you have E09 and ignore it long enough, you can end up with E01 too because a shorted heater can take out the board.
Why did my dishwasher control board fail?
Most of the time it's either a surge or just heat over years of use. These boards sit in a base cabinet and run high current through the heater relay on every single cycle. That generates heat, the solder joints crack or the relay contacts burn out eventually. Surges are the other big cause. I replaced three of these boards in one week after a bad summer storm rolled through the area. If you don't have the dishwasher on a dedicated circuit with surge protection, that's a real vulnerability.
Should I repair this or just buy a new dishwasher?
At $400 for a part on a machine that's already 10 years old, that's a fair question. Here's how I think about it: under 7 years old, repair it without hesitation. Over 10 years old with other issues already, the math starts to favor replacement. Thermador dishwashers are quality machines and usually worth fixing if they're not ancient, but if you've already replaced the pump or door latch in the last couple years, maybe have a conversation with yourself about the total you've spent on it before committing to another big repair.
Models Known to Experience E01 Errors
This repair applies to most Thermador dishwashers with this error code. Common model numbers include: