Four sealed Star burners, two of them ExtraLow-capable for gentle simmering, sit over a True Convection oven of 4.4 cu. ft. on the PRD304WHU, a 30-inch Pro Harmony dual-fuel range. Owners usually notice trouble first at the burners, when a flame will not catch or will not hold at its lowest setting.
Gas on top and electric below behave as two separate systems that merely share a control panel. On the gas side we look at igniters, burner ports and the gas valve; on the electric side, the heating element, convection fan and control board. That keeps the diagnosis from wandering between them.
If the display shows a numbered “E” code, Thermador’s general approach applies: reset it, and call for service if it returns, since the number does not map to one fixed meaning. On an older unit, igniters and oven heating deserve the closest look.
They share the standard burner and igniter hardware, with a gas valve calibrated for very low output. Diagnosis follows the same steps as for any other Star burner.
No added risk that we know of. Thermador documents the short cycle as part of how this model is heated and insulated, so no step is skipped.
Try Thermador's usual reset first. If the same code returns after the reset, book a visit so we can check the oven and control board.
Request a visit online in about a minute or phone our coordinators. Close-in neighborhoods often see a same-day slot; the outer counties usually get the next day across Houston.