Thermador Range Not Heating — Causes & Fix

A Thermador range that will not heat almost always comes down to the oven's Star Burner igniter, the BSH control board, or — on dual-fuel models — the convection element. The igniter is the usual culprit: it can glow and still be too weak to open the gas valve, so the burner lights on the cooktop while the oven stays cold. Thermador's oven runs a closed-loop control that reads the cavity temperature and pulses the igniter and gas valve to hold your setting, so a weak link anywhere in that loop stops the heat and often posts an E-series code.

Likely Causes, Ranked#

1. Star Burner igniter failure#

The oven igniter is a silicon-carbide or silicon-nitride element that has to draw enough current — roughly 3.2 to 3.6 amps — to open the gas safety valve. As it ages its resistance rises and its draw falls, so it can glow a dim orange yet never reach the amperage that lets gas flow. Clamp-meter the current: below about 3.0 amps it is too weak, and a healthy igniter reaches bright orange-white within 60 seconds. Replace with the OEM-spec amperage rating, since Thermador's pentagon Star Burner igniter differs from a standard round one.

2. BSH control board relay#

The board runs the heating cycles, temperature regulation, and safety interlocks, and a failed relay shows up as no response to the controls, erratic temperature swings, or a code that returns right after a power cycle. Inspect it for bulging capacitors, darkened solder joints, or burnt relay contacts, and power-cycle the range at the breaker for ten minutes before condemning it — a fault that comes straight back is a hardware failure, and BSH boards must match the exact model.

3. Convection element open circuit (dual-fuel)#

On dual-fuel models a circular element behind the rear wall surrounds the convection fan and adds heat in convection mode. Measure its resistance — 15-35 ohms is normal, and an infinite reading is an open circuit. A partially failed element heats unevenly, so convection baking comes out with hot and cold zones while standard bake may seem fine.

4. Gas safety valve not responding#

The safety valve only opens once the igniter pulls its rated current, so if the igniter checks out but no gas flows, the valve solenoid itself may be at fault. This is a gas-line repair and belongs with a trained technician, not a DIY swap.

5. E-series sensor or overtemp fault#

Thermador's E-series codes point to a specific part: E1 is an oven temperature sensor open or shorted, E2 is an over-temperature condition caught by the safety thermostat, and E6 is a broil-sensor fault. Record the exact code before power-cycling, since some clear on restart — one that returns within a heating cycle confirms the named part has failed.

A Safety Note and Parts#

Thermador appliances often contain high-voltage components or gas connections. Do not attempt repairs beyond basic inspection unless you have professional training. This symptom is reported across models such as the PRD486WD, PRG486WD, PRD486GD, and PRG366WG. Because Thermador shares the BSH electronics platform, many parts cross-reference with Bosch, which shortens lead times compared with fully proprietary luxury brands — but order by the specific range model, since a range cavity differs from a wall oven.

Thermador oven still cold after checking the igniter draw? Our technicians work luxury ranges daily and carry BSH-platform parts. Book an EasyBear technician.