Samsung wall ovens lock the door before Self Clean begins and keep it locked until the cavity is cool enough to be safe. Samsung’s icon guide lists a Locked Door indicator that lights while this is true. The lock is a motor-driven latch behind the top of the door frame, controlled by a switch and the oven’s temperature sensor. It has three ways to be a problem: it is doing its job on a still-hot oven, it has not been told the oven is cool, or it has failed mechanically. The order of what you do reflects those three.
How Long Is Normal
The cavity of a wall oven, especially a double oven where the other cavity may also be warm, holds heat for a long time after a cleaning cycle. An hour is common; longer in a well-insulated cabinet. The door is meant to stay locked throughout, and the lock indicator is meant to stay lit. Do not pull on the handle. The latch is designed to hold and the handle is not designed to be pulled against it; that is how handles and door glass get broken, and how a very hot door gets opened.
When the Oven Is Cold and Still Locked
Once the cavity is fully cool, which you can check by holding a hand near the door glass, and the display is still showing the lock, the control may not have received the message that the temperature has dropped. With the oven idle, switch its breaker off, leave it off for a few minutes, then restore it. On many models the control re-checks the lock state at start-up and drives the latch open. If it does, run a short bake and make sure the oven heats and the door lock behaves normally afterwards; a control that lost track once may do so again, and a C-24 shown during the clean cycle, which Samsung defines as the oven temperature rising faster than normal, is worth mentioning when you book.
When It Still Will Not Release
A cold oven that stays locked after the breaker reset has a latch motor, a lock switch or a wiring problem, or the latch has jammed against the door. Leave the door alone. Forcing it bends the latch hook, breaks the motor cam or cracks the glass, and turns a small repair into a large one. The lock assembly is reached from above the door frame with the oven pulled partly out of the cabinet and its power isolated, and on a wall oven that is a two-person job. Book it.
The Self-Clean Cycle Itself
Two things reduce the chances of this happening. Before the cycle, remove the racks unless the manual for your model says they can stay, take out the temperature probe, and wipe the heaviest soil from the floor of the cavity; a cycle that has to burn off a thick layer runs hotter for longer. During the cycle, run the range hood or open a window, because the smoke and odor are normal but unpleasant. Avoid starting a self-clean when you will need the oven within the next several hours; the lock will still be engaged. And if the oven throws a C-24 during the cycle, let it end and unlock on its own rather than cutting the power while it is hot, since a door unlocked by a power loss on a hot cavity is exactly what the lock exists to prevent.
Combination Ovens
On Samsung microwave-combination wall ovens the lower cavity self-cleans and locks like any oven, and the microwave above does not lock. If the lower door is locked cold and the microwave section is also unresponsive, the problem may be in the shared control rather than the latch. Do not open the microwave section yourself for any reason; its high-voltage capacitor may stay charged with the power off. Book a Samsung wall oven repair, say when the cycle ended and what the display shows, and tell us whether the breaker reset was tried.