mypros+
Error code reference

Thermador Cooktop Error Code E033B

Right ADB error checking induction module component: inductor activation relay

Thermador codesThermador cooktop codes

Right ADB error checking induction module component: inductor activation relay — cannot connect/disconnect one of the inductors.

First step from the service manual

Make sure that the inductors are properly connected to the ADB in question.

The complete diagnostic procedure includes additional test steps, resistance specifications, wiring diagram references, and component test points.

MyPros+ Max

Get the full diagnostic procedure for E033B.

  • Step-by-step tests with expected resistance, voltage, and continuity values
  • Wiring diagram references and connector pinouts from the OEM service manual
  • Verified part numbers when replacement is required
Get the full procedure

$29/month · Cancel anytime · Or $9.95 3-day pass

What E033B means on a Thermador cooktop

Error code E033B on a Thermador induction cooktop indicates a fault within the right ADB (Analog Digital Board) related to the inductor activation relay. Specifically, the control system has detected that the relay responsible for connecting or disconnecting one of the induction coils (inductors) in the right ADB circuit is failing to operate correctly. The ADB communicates with the induction modules and manages the switching of power to each inductor. When the relay cannot complete its open or close cycle as commanded, the board flags this fault to prevent uncontrolled power delivery to the cooking zone.

The inductor activation relay is a critical switching component. If it fails in the open position, the cooktop zone may not heat at all. If it fails in the closed position, the zone may not be able to shut off properly, which is a more serious condition. The error can stem from a faulty relay on the ADB itself, a wiring issue between the ADB and the induction module, or a loose or damaged connection at the inductor harness. Physical inspection of the wiring and connectors between the right ADB and the affected inductor is the correct starting point before assuming the ADB board or relay requires replacement.

Because this fault is specific to the right ADB, only the cooking zones served by that board will be affected. The left side of the cooktop may continue to operate normally. Technicians should verify connector seating, check for pinched or burnt wiring in the inductor harness, and test relay continuity before condemning the ADB assembly.

Source: manufacturer service documentation.

Common causes of E033B

  1. 01

    Loose or disconnected inductor wiring harness

    Wiring / connection

    The connector linking the inductor coil to the right ADB may have vibrated loose or was not fully seated. This is the first item to inspect, as it is a common cause of relay switching faults.

  2. 02

    Failed inductor activation relay on the ADB

    Part replacement

    The relay on the right ADB that controls inductor switching can fail mechanically or electrically, preventing it from completing its open or close cycle. A failed relay will typically require ADB replacement.

  3. 03

    Damaged or pinched wiring between the ADB and inductor

    Part replacement

    Wiring routed near heat sources or pinch points can develop breaks or shorts that prevent proper relay control signals from reaching the inductor. Inspect the full length of the harness for visible damage.

  4. 04

    Faulty right ADB (Analog Digital Board)

    Part replacement

    If the relay and wiring check out as intact, the ADB itself may have a defect preventing it from correctly driving the relay coil. Board-level failure requires replacement of the right ADB assembly.

  5. 05

    Degraded or corroded connector pins

    Wiring / connection

    Corrosion or heat damage at the connector pins between the ADB and the induction module can increase resistance to the point where the relay circuit cannot function reliably. Cleaning or replacing the connector may resolve the fault.

See the test procedure for each cause

Frequently asked questions about E033B

What does E033B mean on a Thermador cooktop?
E033B indicates that the right ADB has detected a failure in the inductor activation relay, meaning the control board cannot properly connect or disconnect one of the right-side induction coils. This prevents the affected cooking zone from operating safely. The fault points to either a wiring or connection problem between the ADB and the inductor, or a failed relay component on the board itself.
Can I fix E033B myself or do I need a technician?
A knowledgeable DIYer can safely check whether the inductor wiring harness on the right ADB is loose or disconnected, which is the first recommended diagnostic step. However, if the fault is caused by a failed relay or a defective ADB board, those repairs involve disassembling the cooktop and handling high-voltage components, which is best handled by a qualified appliance technician.
Is it safe to keep using my cooktop while E033B is displayed?
The right-side cooking zones affected by the right ADB should not be used while this fault is active. The relay fault means the system cannot reliably control whether the inductor is on or off, which is a potential safety concern. The unaffected left-side zones may continue to operate normally, but confirm this with a technician before relying on them.
Will resetting the cooktop clear error code E033B?
A power reset by turning off the circuit breaker for 30 to 60 seconds may temporarily clear the error, but if the underlying fault in the relay or wiring remains, the code will return once the cooktop is used again. A reset alone is not a repair and should not be relied upon as a solution.
How much does it cost to repair a Thermador cooktop showing E033B?
Repair costs depend on whether the fix is a simple wiring correction or requires replacement of the right ADB assembly. Labor and diagnostic fees typically range from $100 to $200, while an ADB board replacement can add $150 to $400 or more in parts depending on the specific model. Getting a diagnostic visit from a Thermador-authorized technician will provide an accurate estimate for your unit.

Related Thermador cooktop codes

All Thermador cooktop codes
View all 129 Thermador cooktop codes

78,000+ service manuals · 160,000+ error codes · 55+ brands

Get Started

$29/month · Cancel anytime · Or $9.95 3-day pass