Thermador Oven Error Codes: Complete Troubleshooting Guide

Common Symptoms

• Oven control panel displays an E-code (E118, E121, E122, E128, or E010)
• Oven begins preheat then cancels and displays a fault code
• Oven heats unevenly or stops heating mid-cycle without user input
• Door lock engages and will not release — E010 displayed
• Oven runs far hotter or colder than the set temperature before shutting down (E128)

Most Likely Causes

1. 1

   E118 — Lower Oven Temperature Sensor (RTD Probe) Fault

   Error code E118 indicates the control board is reading a resistance value from the lower oven RTD (Resistance Temperature Detector) probe that falls outside the expected range. At 75°F room temperature, a healthy Thermador oven sensor reads approximately 1,080–1,090Ω. A failed sensor reads OL (open circuit), near 0Ω, or drifts to an implausible value like 500Ω or 2,000Ω. The probe is a thin metal rod extending into the oven cavity from the upper rear wall — typically accessible from inside the oven cavity without removing the back panel. On PODS301 and PRODS304 models, two Phillips screws hold the sensor to the rear wall. Disconnect the wiring connector and test the probe terminals in multimeter Ω mode. Thermador/BSH part 00487197 costs $30–$60.

2. 2

   E121 — Bake Element Open Circuit

   E121 means the control board detected an open (broken) circuit in the lower bake element. The relay board attempts to energize the bake element and measures no current flow, logging E121. Visually inspect the bake element inside the oven — look for a visible crack, bubbling, burn-through spot, or arc marks. Even a hairline fracture breaks the circuit. With the oven unplugged and element disconnected, test in Ω mode: a healthy Thermador bake element reads 20–30Ω; OL = failed. On concealed-element models (PRODS304 and some PODS301 variants), the element is beneath the oven floor panel — remove the 4 screws and lift the panel to access it.

3. 3

   E122 — Broil Element Open Circuit

   E122 flags an open circuit in the upper broil (top) heating element. The broil element handles broiling and also contributes to preheat on convection models — a failed broil element on a Thermador convection oven can cause the unit to preheat slowly or trigger E122 immediately when the broil circuit is tested. Healthy resistance for the Thermador broil element is 10–18Ω; OL = failed, replace. E122 can also appear when the broil element develops a partial break (resistance reads 200Ω+ rather than OL) — the element appears intact on visual inspection, but a high-resistance point limits current enough to trigger the fault. Test resistance, not just visual appearance.

4. 4

   E128 — Temperature Runaway (Overtemperature Fault)

   E128 is a safety-critical fault: the oven temperature sensor is reporting a value far above the set temperature, indicating a runaway heating condition. The control board shuts down all heating circuits immediately and logs E128 when the cavity temperature exceeds approximately 625°F (depending on the set point). Two root causes: (1) a shorted temperature sensor that reads 0Ω (the board interprets a short as full heat, commands maximum element power, and the oven overheats); (2) a stuck relay on the control board that keeps the element energized even when the board sends an off command. Test the sensor first — 0Ω at room temperature confirms a shorted RTD probe. If the sensor tests correctly, the control board relay is the suspect and professional diagnosis is recommended.

5. 5

   E010 — Door Lock Fault

   E010 indicates the oven door lock mechanism (used during self-clean cycles) did not reach the locked or unlocked position within the expected time window. Causes include a broken door lock motor, a door lock switch that doesn't actuate (the motor moves but the microswitch doesn't register completion), debris or food residue jamming the lock cam, or a failed door lock wiring harness. On PODS301 and PRODS304 models, the door lock assembly is accessible by removing the oven top trim panel. Check the lock cam for obstruction before assuming motor failure — a simple cleaning resolves E010 in approximately 30% of cases.

Quick DIY Checks

1. 1SAFETY AND CODE RETRIEVAL — Before any hands-on diagnosis, switch off the oven's dedicated circuit breaker at the electrical panel (Thermador electric ovens use 240V/50A). For gas models (PRODS304), also turn off the gas supply valve. With the oven powered on but not running a cycle, access the fault log: on PODS301 and PRODS304, press and hold BAKE + BROIL simultaneously for 5 seconds. The display enters service mode and shows stored fault codes. Record all codes — note the most recent fault first. Press CANCEL to clear active faults. Clearing codes does not fix the underlying fault; the code returns immediately if the failed component is still in circuit.
2. 2E118 — TEST THE RTD TEMPERATURE SENSOR — With the oven unplugged, open the oven door and locate the temperature sensor probe at the upper rear wall of the oven cavity. Remove the two mounting screws and carefully pull the probe out of the cavity (the wiring harness has 8–10 inches of slack). Disconnect the 2-wire connector. Set a multimeter to Ω mode and probe both sensor terminals. At room temperature (approximately 75°F), a healthy Thermador RTD sensor reads 1,080–1,090Ω. A reading below 900Ω, above 1,200Ω, OL, or near 0Ω indicates a failed sensor. Replacement: BSH part 00487197 — $30–$60. This is one of the easiest Thermador repairs, requiring only a Phillips screwdriver.
3. 3E121 — INSPECT AND TEST THE BAKE ELEMENT — With the oven unplugged, visually inspect the bake element for cracks, burn-through, or arc marks. On exposed-element models (most PODS301 configurations), remove the two rear-wall mounting screws, pull the element forward to reveal the wire connectors, and disconnect both. Test both terminals in Ω mode: healthy = 20–30Ω, failed = OL. On concealed-element models, remove the 4 oven floor panel screws first, lift out the panel, then access the element. Thermador bake elements are model-specific — photograph the part number label before ordering a replacement ($40–$75).

Repair vs Replace

Recommended Tools & Parts

• Thermador Oven Temperature Sensor / RTD Probe (BSH 00487197)

  Replacement RTD temperature sensor for Thermador electric wall ovens and ranges. Fixes E118 error code. Healthy resistance: approximately 1,080–1,090Ω at 75°F. Compatible with PODS301, PRODS304, MED301, and related BSH platform models. Amazon tag: fixitfastai-20.

  $30–$60

  Buy on Amazon →

• Thermador Bake Element (Electric Wall Ovens)

  Replacement bake element for Thermador electric wall ovens. Fixes E121 error code and no lower heat. Healthy resistance: 20–30Ω. Model-specific — verify by full model and production date (FD) code on the oven label. Amazon tag: fixitfastai-20.

  $40–$75

  Buy on Amazon →

• Thermador Broil Element (Electric Wall Ovens)

  Replacement upper broil element for Thermador electric wall ovens. Fixes E122 error code and no-broil condition. Healthy resistance: 10–18Ω. Verify model number before ordering. Amazon tag: fixitfastai-20.

  $45–$85

  Buy on Amazon →

• Digital Multimeter

  Required for testing RTD sensor resistance (1,080–1,090Ω spec), bake element (20–30Ω), and broil element (10–18Ω). Essential for distinguishing sensor faults from element faults before ordering parts.

  $20–$45

  Buy on Amazon →

Links are Amazon affiliate links (tag: fixitfastai-20). Prices are estimates.

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