The Dryer Stopped Repeatedly and Barely Heated in Time Dry
A vented Bosch electric dryer ran for several minutes, stopped, restarted and eventually remained at Wrinkle Block/End. Removing the external vent did not settle the diagnosis because heat was still weak and intake airflow remained questionable.
Why Time Dry changed the diagnosis
A moisture-sensing problem can end an automatic cycle early. In this case, however, the machine also produced very weak heat in Time Dry. That observation made a moisture-sensor-only explanation less convincing and moved airflow, heater temperature feedback, limits, relay and supply higher on the list.
A similar symptom can have a different cause on another Bosch dryer. The displayed Wrinkle Block/End state does not, by itself, identify a failed thermistor or control board.
What each observation did—and did not—prove
The external vent was disconnected
This reduced one restriction, but did not prove that the lint path, blower inlet or internal duct was clear.
Time Dry was also weak
That made a moisture-sensor-only theory weaker because timed operation should not depend on dryness feedback in the same way.
The small sensor was temperature feedback
Its role needed to be identified from the model documentation rather than from its location or appearance.
A hi-limit can be the result
Replacing an opened limit without finding repeated overheating or bad feedback can produce another failure.
A safer diagnostic order
- Record the full model, selected cycle and time to the first stop.
- Compare an automatic cycle with Time Dry and note whether heat disappears in both.
- Inspect the accessible lint filter and the complete external vent path.
- With power disconnected, inspect the internal airflow path, connectors and signs of overheating.
- Test the heater, thermal limits and temperature sensors against model-specific values.
- If a hi-limit failed again after replacement, find the heat or feedback cause before installing another.
- Evaluate relay and control output only after airflow, supply and load checks.
What the second technician's result adds
A technician in the same discussion described a similar Bosch pattern: a hi-limit was replaced, failed again two days later, and the dryer operated normally after the black thermistor on the heater was replaced. That is useful corroboration for the temperature- feedback branch.
It is not proof that the opening dryer needed the same part. The opening technician had not yet reported a completed repair, and the full heater assembly, wiring and airflow still required model-specific testing.