Bosch Dryer Won't Stop: Causes & Fix

Quick Answer: Why Your Bosch Dryer Won't Shut Off#

Most likely: the moisture sensor bars are dirty. Bosch's AutoDry cycle ends when the two sensor bars read the load as dry, and when fabric-softener film or mineral scale coats them they read "still wet" and the cycle never finishes. Cleaning those bars resolves nearly half of all "won't stop" complaints, so it is the first thing to do. After that, the remaining causes are a moisture sensor that has failed electrically, a control board stuck in a cycle loop, and — not a fault at all — a genuinely soaked or dense load that simply takes a long time to dry.

Likely Causes at a Glance#

Walking Through the Diagnosis#

Start at the sensor bars, because they cause almost half of these. Find the two metal strips inside the drum and clean them with white vinegar and fine 400-grit sandpaper until the fabric-softener film is gone; a fouled bar tells the board there is still moisture, so AutoDry keeps running indefinitely. This single step ends most cases.

If it still will not stop after cleaning, separate the sensor from the logic with a simple test: run a Timed Dry cycle, which uses a fixed duration and ignores the sensors. If Timed Dry ends normally but AutoDry does not, the moisture-sensor system has failed electrically — it reads "wet" no matter what — and the sensor is replaced. If even Timed Dry will not end, or the dryer shows other odd behavior like display glitches, the control board is stuck in a cycle state; power-cycle it by unplugging for a minute, and if the problem clears then returns, the board has an intermittent logic fault. Two more to weigh: a legitimately very wet or dense load — say, items wrung out by hand with no spin — just takes far longer, so check every half hour and confirm the clothes are actually getting drier (a heat-pump Bosch running around 65°C is gentle and slow on saturated items). And in the rare case where the drum keeps spinning even with the program selector turned to Off, a board relay powering the motor has welded shut — unplug the dryer immediately, as that needs a board replacement.

Repair or Replace? The Short Version#

The most common fix here is free — cleaning the sensor bars — and clearly worth trying before anything else on a dryer that otherwise works. A replacement moisture sensor is inexpensive, and only the control board approaches real cost, still well under a new dryer. The one urgent case is a stuck motor relay: if the drum will not stop at Off, unplug it and treat it as a board fault. Otherwise a cycle that merely runs long is low-risk but worth fixing to spare the components — book a repair.

Frequently Asked Questions#

My Bosch dryer has run for hours — should I stop it?#

Check the clothes first. If they are getting steadily drier, the dryer is just working through a heavy, wet load and is fine. If they are already bone dry and it keeps running, the moisture sensors are not detecting dryness — stop the cycle and clean the two sensor bars with vinegar and fine sandpaper.

How do I tell a dirty sensor from a failed one?#

Clean the bars, then run a Timed Dry cycle. Timed Dry ignores the sensors and ends on a fixed timer, so if it finishes normally while AutoDry still runs forever, the moisture sensor has failed electrically and needs replacing rather than just cleaning.

Is a Bosch dryer that won't stop a fire risk?#

If the clothes and cabinet are getting very hot, stop it immediately — that is overheating. If the temperature is normal and the cycle simply is not ending, the risk is low, but you should still fix it: prolonged running adds heat stress and lint accumulation over time, so clean the sensors or address the board fault.

The drum keeps spinning even when I turn it to Off — what's that?#

That is the rare but serious case: a control-board relay powering the motor has welded shut, so the motor runs regardless of the selector. Unplug the dryer right away, since it cannot be stopped at the panel, and have the control board replaced.