# Northbank Kitchen Service — (904) 395-4339 > Independent Thermador speed oven repair across Jacksonville and Duval County. Door latches, cooling fans and boards, with a written estimate first. Source page: https://jaxthermador.com/fix/speed-oven/ Title: Thermador Speed Oven Repair in Jacksonville --- Speed ovens ## Thermador Speed Oven Repair in Jacksonville Speed ovens that run but never brown, trip their latch, or shut down hot. Diagnosed in the cabinet. ### Symptoms we get called for - Oven runs the full cycle but the food comes out cold - Unit shuts down part way through and will not restart until it cools - Loud hum on microwave power that was not there before - Door does not latch cleanly and the cycle refuses to start - Cooling fan runs on for a long time after every cycle - Convection element heats but the fan behind the rear panel is silent A speed oven is two appliances sharing a cavity. There is a microwave side and a convection side, and a control board deciding how much of each to use. When a speed oven disappoints, the first job is working out which half stopped. That is easy to test. Run a short convection-only cycle and feel the cavity. Then run a microwave-only cycle with a cup of water. Whichever one does nothing is where the fault is. ### Runs but does not heat If the display counts down, the fan turns and nothing gets hot, the microwave side has usually dropped out. That circuit is high voltage and it is not a homeowner repair under any circumstances. The capacitor in a microwave circuit holds a lethal charge after the appliance is unplugged. We discharge it as a matter of routine before anything else happens. The common failures are the magnetron, the high-voltage diode, the capacitor, or one of the door interlock switches. They fail in different ways and only one of them is expensive, so the test order matters. ### Thermal shutdowns A speed oven that stops mid-cycle and refuses to restart until it has cooled is protecting itself. Built-in installations make this worse. Speed ovens are frequently stacked over a wall oven or set into a tall cabinet with limited clearance. If the vent path in front of or below the unit is obstructed — a trim kit fitted wrong, a filler panel added later, a drawer packed tight behind it — the electronics sit in their own exhaust. In Jacksonville’s older kitchens this is common. Riverside, Avondale and San Marco cabinetry was not built around a modern speed oven, and retrofits often lose the clearance the appliance needs. Where the install is at fault, we say so. Replacing a board that failed from heat only buys time. ### Door latches and interlocks A speed oven will not fire the microwave side unless every interlock switch agrees the door is shut. That is a safety design, and it works. A door that has dropped slightly, a worn latch hook, or a single failed switch produces the same complaint: the cycle will not start, or it starts and stops. Never defeat an interlock. A microwave cavity with a compromised door is a radiation problem, not an inconvenience. ### Noise A new, loud hum under microwave power usually means the magnetron or the transformer is on its way out. It is a distinctive sound and it does not get better. A grinding or droning noise that continues after the cycle ends is the cooling fan. Speed ovens run their fan on after every cycle by design, so a long run-on is normal. A noisy run-on is not. ### Touch panel and boards Thunderstorm season here runs long, and Jacksonville sees roughly 68 thunderstorm days a year. Control boards in built-in ovens take the brunt of that. A speed oven that came back from a storm with a dead panel, phantom presses or a display that lights but does not respond is usually a board. We test the supply before fitting a board. Putting a new one behind an unstable circuit wastes your money. ### What the visit costs Flat $80 diagnostic, credited toward the repair. Written estimate before any part is ordered. Genuine OEM parts. Labor carries 90 days, parts carry 365. Monday to Friday 8am to 6pm, Saturday 9am to 4pm. Areas covered ### Where we go [Every area we cover](https://jaxthermador.com/where-we-go/) ### Briefs on this - [Storm Season and Built-In Control Boards](https://jaxthermador.com/briefs/storm-season-and-control-boards/) Duval County sees around 68 thunderstorm days a year. Here is what repeated interruptions do to Thermador control boards, and how we test before replacing. ### Also on the van Speed ovens ### What owners said after this repair - ★★★★☆ The turntable had stopped turning and the display was flickering. He sorted the drive motor the same afternoon, and the flicker turned out to be a loose ribbon behind the panel. Cable dressing at the end was a bit untidy. Barnabas U. 2026-07-05 - ★★★★★ The speed oven ran its fan but produced no heat at all in combination mode. He identified the magnetron circuit, made the safety checks in front of me, and replaced the assembly with the right part first time. Wilhelmina Q. 2026-08-01 - ★★★★★ The unit was cooking unevenly and the fan sounded strained. He found the convection element part open and the blade rubbing its shroud. Both were dealt with, and he vacuumed the cabinet out before he left. Thornton I. 2026-06-01 [Every review we publish](https://jaxthermador.com/reviews/) Flat $80 diagnostic, credited to the repair. [Call (904) 395-4339](tel:+19043954339) ![A technician kneeling at an open wall-oven cavity with his hands at the hinge receivers and tools laid out on the counter above](https://jaxthermador.com/img/jax-walloven-door-01-a.webp) *From the visit: A speed oven is still an oven: seal, hinge and latch get checked before the electronics do.* --- Booking is by telephone: (904) 395-4339. This Markdown file is a plain-text mirror of https://jaxthermador.com/fix/speed-oven/, published so a language model can quote the page without parsing its HTML. The page itself is the authority if the two ever differ.