Bosch WTG115 Dryer Emits Smoke When Heating

Identifying the Issue

When a Bosch WTG115 dryer starts to emit smoke during operation, the first reaction for most homeowners is concern and urgency. A sudden puff of smoke is a clear indicator that something inside the appliance is not functioning as intended. Before any action is taken, it is essential to turn off the dryer immediately, disconnect it from the power source, and allow it to cool completely. The smoke itself is often the result of lint accumulation, overheating, or a malfunctioning component such as the heating element or blower motor.

Recognizing the type of smoke can also give clues. White, pale smoke usually points to burning lint, while black smoke may indicate overheating of electrical components. A distinct metallic scent may suggest an issue with the heating element, whereas a sweet or chemical odor could point to a malfunctioning motor or a damaged plastic part.

Common Causes of Smoke in the Bosch WTG115 Dryer

1. Lint Blockage

Lint is the most frequent culprit. Even if the lint filter appears clear, lint can accumulate in the dryer vent, heat exchanger, or exhaust duct. Over time, this blockage reduces airflow, causing the drum and heating element to overheat and produce smoke.

2. Faulty Heating Element

The Bosch WTG115 uses a gas or electric heating element to warm the air that circulates through the drum. A damaged or shorted element can generate excessive heat, burning any dust or debris that has accumulated in its vicinity.

3. Malfunctioning Blower Motor

The blower motor pushes heated air through the venting system. If it fails, air cannot exit the dryer, again leading to overheating and the potential for smoke.

4. Electrical Short or Wiring Issues

Faulty wiring or a short in the control board can cause arcing and smoke. This is less common but should never be ignored, especially if the smoke occurs before the dryer reaches operating temperature.

5. Mechanical Failure in the Drum Bearings

Worn or damaged bearings may cause the drum to bind, increasing friction. The resulting heat can lead to a small fire or smoke if the heat is not dissipated properly.

6. Improper Load Size or Placement

Overloading the dryer or leaving heavy items on one side can disrupt airflow, causing uneven heating and the potential for localized hot spots that ignite lint.

Safety First: Immediate Actions

1. Turn Off the Dryer
   Power down the unit by pressing the reset or cancel button, then switch the electrical outlet off or the gas valve on.

2. Disconnect the Power Source
   Unplug the dryer or turn off the circuit breaker. For gas models, shut off the gas supply valve.

3. Ventilate the Area
   Open windows or use a fan to disperse any lingering fumes.

4. Inspect Visually
   Once the dryer has cooled, check for visible signs of smoke, discoloration, or damage. Do not operate the dryer until a professional has inspected it.

5. Do Not Attempt to Fix Complex Issues
   While cleaning the lint filter is straightforward, attempting to replace the heating element or blower motor without proper knowledge can be hazardous.

Step‑by‑Step Troubleshooting Guide

1. Verify the Lint Filter and Vent Path

• Remove the Lint Filter
  Pull it out of the front compartment and remove all lint. Clean the filter’s screen with a damp cloth and let it dry completely.

• Check the Vent Duct
  Follow the vent from the dryer to the exterior. Ensure it is free of obstructions, is not kinked, and is at least 3–4 feet long. Use a vent cleaning brush or a vacuum with a long hose attachment to clear any debris.

• Inspect the Heat Exchanger
  If you have access, remove the back panel of the dryer and check the heat exchanger for lint buildup. A simple brush or a can of compressed air can remove any residue.

2. Examine the Heating Element

• Locate the Element
  For electric models, the element is a coiled metal wire located behind the back panel. For gas models, it is a tube with small burners.

• Look for Damage
  A broken or discolored element will appear mottled or have visible cracks. Do not attempt to repair an element; replace it with a Bosch‑approved part.

3. Test the Blower Motor

• Manual Rotation
  With the dryer unplugged, try to turn the motor shaft by hand. It should rotate smoothly. Resistance or grinding noises indicate a motor failure.

• Check for Power
  Use a multimeter to verify that the motor receives the correct voltage when the dryer is switched on.

4. Assess the Drum Bearings

• Listen for Noise
  When the dryer starts, a worn bearing often produces a squealing or grinding sound. If you hear this, the bearings should be replaced.

• Feel for Vibration
  A heavy vibration during operation also suggests bearing wear.

5. Inspect the Control Board and Wiring

• Look for Burn Marks
  On the internal control board, check for scorch marks or melted plastic. These are signs of an electrical fault.

• Test Voltage
  Use a multimeter to test the power supply lines to the board. Verify that they match the manufacturer’s specifications.

6. Conduct a Dry‑Run Test

After completing all inspections, reassemble the dryer, reconnect the power, and run a short cycle without any load. Observe if smoke reappears. If it does not, the problem likely lies in one of the previously checked areas. If smoke returns, it is safer to have a professional technician diagnose the issue.

When Professional Help is Needed

If the problem persists after thorough cleaning and inspection, or if you encounter any of the following, contact a qualified appliance repair technician:

• Electrical Issues – Any sign of sparking, burning, or melted wires.
• Gas Appliance Concerns – Smell of gas, leaks, or flame irregularities.
• Persistent Smoke – Even after cleaning lint and checking the heating element.
• Structural Damage – Cracked components or damaged panels.

An experienced technician will have specialized tools, such as infrared cameras to detect hot spots, and the knowledge to replace parts safely.

Warranty and Service Considerations

Bosch appliances typically come with a limited one‑year warranty that covers parts and labor for defects. If your dryer is still under warranty, do not attempt repairs yourself, as this may void coverage. Instead, contact Bosch customer support or an authorized service center. If the issue is due to wear and tear, it may not be covered, but service agreements can still offer discounted rates for repairs.

Preventive Measures to Avoid Future Incidents

Regular Lint Removal

• Daily – Remove lint from the filter after each cycle.
• Weekly – Inspect the lint filter and clean it with a brush.
• Monthly – Vacuum the vent duct and heat exchanger.

Keep the Dryer Door Open

After each use, leave the dryer door slightly ajar for a few minutes to allow the drum to cool and to reduce condensation that can foster mold growth.

Monitor Load Sizes

Do not overload the dryer. The manufacturer’s guidelines typically specify a maximum load weight. Excessive weight can cause uneven airflow and increased heat build‑up.

Schedule Routine Maintenance

At least once a year, schedule a professional inspection. They can check electrical connections, test motor health, and ensure all components are functioning correctly.

Replace Old or Worn Parts Promptly

If you notice any signs of wear—like loose screws, squeaky bearings, or uneven drum rotation—replace the parts before they cause larger issues.

Common Myths Debunked

• Myth: A dryer that smokes once is normal.
  Reality: Any smoke emission is a warning signal. The dryer is not designed to produce smoke.

• Myth: You can just wipe the smoke residue with a cloth.
  Reality: Residue may contain hot, flammable particles that can ignite if disturbed. Professional cleaning is safer.

• Myth: Cleaning the lint filter is the only thing needed.
  Reality: The entire vent system, heat exchanger, and internal components must be checked.

Final Thoughts

A Bosch WTG115 dryer emitting smoke is a clear indication of a serious problem that requires immediate attention. By acting quickly, prioritizing safety, and methodically checking each potential cause, homeowners can often identify the root issue. While cleaning lint and inspecting the heating element are usually sufficient, many cases demand a professional technician’s expertise. Maintaining a regular cleaning schedule, monitoring load sizes, and scheduling periodic professional inspections will help keep your dryer operating safely and efficiently for years to come.