Bosch Dryer Cycle Not Completing — AutoDry Sensor, Drain & Board Diagnosis

Bosch compact dryers (WTW heat pump and WGA condenser series) use AutoDry technology that automatically ends the cycle when moisture sensors detect clothes are dry. When a cycle stops prematurely, it is usually the AutoDry system misreading moisture levels, the condensate drain system triggering a safety stop, or the control board detecting an error condition.

How Bosch AutoDry Works

Two stainless steel sensor bars inside the drum measure electrical conductivity between them through the tumbling clothes. Wet fabric conducts electricity; dry fabric does not. The control board monitors this conductivity and ends the cycle when readings indicate the selected dryness level has been reached.

Most Common Causes

1. Dirty or Coated Moisture Sensors (35% of cases)

Fabric softener, dryer sheet residue, and mineral deposits from hard water coat the sensor bars, reducing their ability to detect moisture. The coated sensors read lower conductivity (appearing as dry clothes) and end the cycle prematurely.

Locate the sensors: Two parallel metal bars inside the drum, visible below the door opening on the front bulkhead. Clean with white vinegar on a cloth, then fine sandpaper (400-grit) to remove stubborn buildup. Bosch recommends cleaning sensors every 3 months.

DIY Difficulty: Easy — no tools needed Parts Cost: $0 Professional Repair Cost: $89–$120

2. Condensate Drain Full or Blocked (25% of cases)

Bosch ventless dryers extract moisture from clothes as water. This water either goes to a removable collection tank (top of unit) or drains directly to plumbing (if connected). When the tank is full, the dryer displays E:08 and stops. When the drain hose is kinked or blocked, pressure builds and the drain pump triggers a fault.

Check: Is the condensate tank indicator lit on the display? Empty the tank. If direct-drain connected, verify the drain hose is not kinked and flows freely. Run water through the hose to test for blockages.

The drain pump (BSH 00145787) can also fail — if you hear the pump running but water does not drain, the pump impeller may be jammed with lint. Access pump through the front lower service panel.

DIY Difficulty: Easy (tank/hose) or Moderate (pump) Parts Cost: $0 (cleaning) or $45–$80 (pump) Professional Repair Cost: $89–$200

3. Heat Pump Overheating — Thermal Cutout (20% of cases)

Bosch WTW heat pump dryers have a thermal cutout that shuts down the compressor if the heat pump circuit overheats. This typically results from lint-clogged condenser fins restricting airflow. The dryer stops mid-cycle, often displaying E:04 (heat pump fault).

The dryer may restart after cooling for 30–60 minutes (thermal cutout resets), but will stop again at the same point — indicating the heat path restriction is consistent.

Fix: Clean the condenser (pull out from front bottom panel, vacuum fins). If the thermal cutout has tripped repeatedly, it may need replacement — BSH part specific to model, approximately $20–$40.

DIY Difficulty: Easy (condenser cleaning) Parts Cost: $0 (cleaning) or $20–$40 (cutout) Professional Repair Cost: $120–$250

4. Control Board Error (12% of cases)

The control board manages all dryer functions including cycle timing, sensor monitoring, and heat pump control. Board-level faults can cause random cycle stops with or without error codes. Common errors: E:03 (NTC sensor fault), E:09 (communication error between main board and display board).

If the dryer stops at different points each time with varying or no error codes, the board has an intermittent fault. Power cycling (unplug 60 seconds) may clear transient errors, but recurring issues require board replacement.

DIY Difficulty: Moderate Parts Cost: $150–$350 Professional Repair Cost: $280–$500

5. Door Switch Intermittent Failure (8% of cases)

The door switch must confirm the door is closed throughout the cycle. An intermittent switch briefly signals door-open, pausing or stopping the cycle. Vibration from the drum can trigger a marginal switch.

Test: Start a cycle and gently push on the door. If the cycle pauses or the drum stops, the switch or its alignment is failing.

DIY Difficulty: Easy to Moderate Parts Cost: $15–$35 Professional Repair Cost: $89–$180

Bosch Dryer Error Codes (Cycle Stop)

Step-by-Step Troubleshooting

1. Check for error codes on display when cycle stops. Record the code.
2. Empty condensate tank if indicator is lit.
3. Clean moisture sensors inside drum with vinegar and 400-grit sandpaper.
4. Pull out and clean the condenser — vacuum lint from heat exchanger fins.
5. Power cycle — unplug 60 seconds, restart.
6. If recurring at same time: Thermal cutout or heat pump fault. Professional diagnosis recommended.

DIY Fix vs Professional Repair

FAQ

Q: My Bosch dryer stops after 10 minutes with E:08. What does this mean?

E:08 means the condensate collection tank is full. Empty the tank (pull out from top of dryer). If the tank is not full, the float sensor inside may be stuck — clean it. If connected to direct drain, check for kinked or blocked drain hose.

Q: Clothes are still damp when my Bosch dryer says the cycle is complete. Why?

AutoDry sensors are coated with fabric softener or mineral residue, reading clothes as drier than they are. Clean both sensor bars with vinegar and 400-grit sandpaper. Also try selecting a higher dryness level (Extra Dry instead of Normal).

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Bosch dryer stopping mid-cycle? Our technicians diagnose AutoDry sensors, heat pump faults, and drain issues on all WTW and WGA models. Schedule a repair →