Bosch WTG100 Dryer Overheats and Shuts Down Early

Overview

When a Bosch WTG100 dryer stops mid‑cycle and turns off, it can feel like a mysterious electrical glitch. The most common culprit is overheating, which triggers a safety shut‑off to protect the machine and your home. This article explores why the WTG100 behaves this way, how to identify the symptoms, and step‑by‑step actions to reset or repair the unit. By following these guidelines, you can restore dryer performance while avoiding costly repairs or dangerous fire hazards.

Recognizing the Problem

A dryer that shuts down early typically displays one or more of the following signs:

• Abrupt power loss – The motor stops, the drum stops turning, and the display turns blank before the cycle ends.
• Heat‑related indicator – Many Bosch models show a warning icon or a red light when the internal temperature rises beyond safe limits.
• Unusual smells – A lingering odor of hot plastic or burnt plastic signals that components are overheating.
• Repeated cycles – If the dryer repeatedly stops after a short period, it is likely the temperature sensor detecting a spike.

If you observe any of these signs, note when they occur and whether the dryer was loaded with heavy or damp laundry. These details help narrow down the root cause.

Common Causes of Overheating

Restricted Ventilation

The most frequent cause is a blocked or partially blocked vent. The dryer exhausts hot air and lint through a duct that leads outside. If lint accumulates in the duct, the airflow slows, raising the internal temperature. Even a partially clogged vent can trigger the thermal fuse, causing the machine to shut down.

Faulty Heating Element

The heating element in the WTG100 uses electricity to generate heat. If it is damaged or has a short circuit, it may draw excessive current, causing the element to overheat. The thermal sensor will cut power to protect the dryer.

Defective Temperature Sensor

Bosch dryers rely on a temperature sensor (thermistor) to monitor internal heat. A malfunctioning sensor may misread temperatures and incorrectly signal an overload, leading to an early shut‑off.

Power Supply Issues

An unstable voltage supply or a tripped circuit breaker can cause irregular power delivery. While this rarely results in overheating, inconsistent voltage can damage internal components, leading to overheating over time.

Mechanical Wear

Worn drum rollers, a failing motor, or an imbalanced load can create friction that generates heat. If the motor stalls, the sensor may register a spike, causing the dryer to shut down.

How to Diagnose the Issue

Below is a practical checklist to help you pinpoint the root problem. Follow each step carefully and proceed only after confirming the previous steps are resolved.

1. Inspect the Vent Path

1. Unplug the dryer and locate the vent at the back.
2. Carefully detach the vent and check for lint buildup.
3. Use a vacuum or a brush to clean the vent and the entire duct to the exterior.
4. Reattach the vent, ensuring it is securely connected.

If you find significant lint, this is the most probable cause. Clean the vent again after a few days to confirm the issue is resolved.

2. Verify the Power Supply

1. Check the outlet with a voltage tester to ensure it reads 120 V ± 5 %.
2. Confirm the breaker has not tripped and that the outlet is not overloaded.
3. If you suspect a problem, consider using a dedicated outlet for the dryer.

An inconsistent supply can lead to abnormal heating over time.

3. Test the Heating Element

1. Use a multimeter set to resistance (Ω).
2. Locate the heating element (usually near the top of the dryer).
3. With the dryer unplugged, disconnect the element’s wires.
4. Measure resistance between the two terminals.
5. The reading should be within the manufacturer’s specified range (often around 25 Ω).
6. A reading of infinite or zero indicates a fault.

If the element fails this test, replace it before continuing.

4. Check the Temperature Sensor

1. Locate the thermistor near the heating element.
2. Disconnect it and measure resistance at room temperature.
3. The expected value is typically between 3 kΩ and 5 kΩ.
4. Compare the reading to the manufacturer’s data sheet.

A defective sensor may require replacement. If you are unsure, contact Bosch support for the correct part number.

5. Examine the Drum and Motor

1. Inspect the drum rollers and idler pulley for smooth rotation.
2. If they wobble or squeak, they may be worn.
3. Test the motor by applying a temporary power source to confirm it runs freely.
4. Look for any signs of overheating (burnt smell, discoloration).

Replacing worn rollers or motor bearings is usually straightforward.

Resetting the Dryer

After addressing the cause, you may need to reset the dryer’s thermal protection system:

1. Unplug the dryer for at least one minute.
2. Re‑plug the unit.
3. Turn the power back on and start a short cycle.
4. Observe whether the dryer completes the cycle or shuts down again.

If the dryer still shuts down, revisit the diagnostic steps. In rare cases, the thermal fuse may be permanently blown and needs replacement.

Preventive Measures

Regular Vent Cleaning

Schedule a lint and vent inspection at least twice a year. Even a small amount of lint can impair airflow and raise temperature. A quick vacuum or brush every few months keeps the system efficient.

Proper Load Size

Avoid overloading the dryer. A cramped drum forces the motor to work harder, generating excess heat. Follow the capacity guidelines on the dryer’s label or in the user manual.

Use Correct Cycle Settings

For heavy or damp clothes, select a high‑heat or tumble‑dry cycle. Lower‑heat cycles may not generate enough warmth to dry clothes properly, causing the dryer to cycle longer and produce more heat.

Monitor the Cycle

If you notice a red warning light or a sudden drop in temperature during operation, pause the cycle. Checking the vent and sensor may catch problems early.

When to Call a Professional

Even with thorough troubleshooting, some issues require expert attention:

• Electrical faults – If the dryer has a persistent power problem or a burnt smell near the outlet.
• Major component failures – Replacing the heating element, motor, or internal wiring is complex and safer for a licensed technician.
• Warranty claims – Bosch appliances are covered under a limited warranty. Contact Bosch service if the dryer is still under warranty and the problem persists.

Professional technicians have specialized tools for measuring electrical parameters safely and can provide proper replacement parts.

Warranty and Replacement

Bosch offers a limited warranty on new WTG100 units, typically covering parts for 12 months and labor for 6 months. If your dryer is beyond warranty and you have determined the cause, consider the following:

1. Purchase a new dryer – If repair costs exceed 50 % of the price of a new unit, replacement is often more cost‑effective.
2. Shop for reputable sellers – Look for certified Bosch dealers or reputable appliance stores.
3. Check for recalls – Rarely, Bosch may issue a recall for a particular model. Verify with Bosch’s official website or customer service.

Frequently Asked Questions

Why does the dryer keep shutting off on me?

An over‑temperature protection mechanism is designed to shut the unit down when internal heat rises too high. Common causes include lint‑blocked vents, faulty heating elements, or sensor malfunctions.

Can I ignore a sudden shut‑off?

No. Ignoring it can lead to further damage or fire hazards. Immediately unplug the dryer and investigate.

Does unplugging reset the thermal fuse?

It can reset a temporary thermal switch but will not replace a permanently blown fuse. If the dryer continues to fail after a reset, replace the fuse or sensor.

Is it safe to use a different outlet?

Only if the outlet is on a dedicated circuit rated for 120 V, 20 A, and properly grounded. Avoid using a shared or overloaded outlet.

How long does a Bosch dryer typically last?

With proper maintenance, Bosch dryers can last 10‑15 years. The key is regular cleaning and prompt attention to warning signals.

Conclusion

An overheating Bosch WTG100 dryer that shuts down early is a safety feature that protects your home and the appliance. By systematically checking the vent, heating element, temperature sensor, and power supply, you can often identify and fix the problem without professional help. Regular maintenance, correct load sizes, and attentive use will extend the dryer’s lifespan and reduce the likelihood of sudden failures.

When in doubt, consult a certified Bosch technician or your local appliance repair service. Taking proactive steps ensures your dryer operates safely, efficiently, and reliably for years to come.