Bosch Dryer E13 Error Code DIY Troubleshooting Guide

Seeing an E13 error code appear on your Bosch dryer can be confusing and concerning. But don’t worry – this post will guide you through what causes an E13 error, and provide fix-it tips to get your dryer heating and tumbling properly again.

If you find out that you need any replacement parts for your appliance while you’re troubleshooting, you can enter your model number at AppliancePartsPros.com to order them. Most orders arrive in just two business days, and we have thousands of free guides to show you how to install your new parts.

The information in this article may not apply to your specific appliance model. We recommend consulting your manufacturer’s documentation or contact us with any questions.

What triggers the E13 error code?

The E13 error code indicates that the maximum drying time has been exceeded on your Bosch dryer model. It is essentially a timeout error.

There are a few common reasons why you may see an E13 error:

• The heating element has failed or is not working correctly. This could be the electric heating coil on electric models, or the igniter and gas valve on gas models.
• The load is too large or heavy for the drying cycle. Overloading the drum prevents clothes from drying effectively.
• Lint buildup or restriction in the ductwork is causing the dryer to run much longer than normal to dry a load.
• The external venting has a blockage or is disconnected.
• Thermistors or sensors are faulty, providing inaccurate readings.
• The control board has defective relay circuits.

When any of these conditions occur, the drying time exceeds the maximum limit programmed into the control board. Typically the max run time is between 90 to 130 minutes, depending on settings. Once the drying cycle goes over the limit, the E13 error shuts down the dryer for safety.

Safety precautions

When working on any appliance, remember to keep safety first. Here are some tips to keep in mind: 

• Always power off and unplug your appliance or switch off the circuit breaker before attempting any maintenance or replacement work. This keeps you safe by preventing any risk of injury from electric shock.
• Wear insulated work gloves to protect your hands from sharp metal parts, pinching hazards and debris.
• Take your time and don’t rush while working to prevent accidents and personal injuries.
• Work in a well-lit area so you can clearly see and access the interior parts.
• Clear your workspace of clutter and other obstacles. Keep children and pets away from the work area.
• Never work on internal parts with bare wet hands. Make sure the work area is completely dry.
• Check your user manual to see if there are specific installation or safety instructions for your part or appliance. 
• Be gentle when handling or removing parts. Excessive force might damage the appliance or cause injury.
• Wear safety glasses when working with chemicals, dust or cleaning large debris to prevent injury. 
• If the appliance has recently been used, give it plenty of time for any heating parts to cool down before working on it. 
• Take pictures or make a note of wiring terminals or other connections before disconnecting to prevent any problems with reassembly.
• When working with wires, avoid touching any exposed wires or terminals. If you need to touch a wire, use a non-conductive tool or wear insulating gloves to prevent electrical shock.
• Don’t test wiring with a multimeter for live voltage if you’re unfamiliar with how to prevent short circuiting when testing. 

Troubleshooting steps

Step 1: Test the heating element

1. Test for proper voltage from the main control to the element during operation.
2. Carefully inspect the heating element for any visible damage, charring, or broken coils.
3. Use a multimeter to check the continuity through the heating element circuit.
4. Detach the wire leads from the heating element terminals.
5. Set the multimeter to the ohms setting and touch the probes to the element terminals.
6. A good element will show a low and steady ohm reading, usually between 10 to 20 ohms.
7. If the reading is “OL” or infinite, the circuit is broken and the element is bad.
8. One break anywhere means the whole heating element needs replacement.
9. Reattach the wire leads to the heating element terminals.
10. Restore power to the dryer.

LIVE VOLTAGE WARNING: For this test, the dryer needs to be plugged in and powered on. Please be very careful to protect yourself from electric shock, which has the potential to cause serious injuries. Don’t ever test live voltage if you’re uncomfortable using a multimeter.

1. Test for proper voltage to the element during operation.
2. Voltage should match the dryer rating spec: 240V for electric or 120V for gas burners.
3. No voltage points to a bad heating circuit relay on the control board.

Step 2: Adjust load size and content

1. Consult your dryer’s owner’s manual to determine the rated capacity limits for the drum.
2. As a general rule of thumb, the drum should be 50-75% full with space between items.
3. The clothes should be able to lift and tumble freely when the dryer is running.
4. Separate large loads into smaller batches to prevent overloading.
5. Take extra heavy items like blankets and comforters to a laundromat with oversized commercial dryers.
6. Try to wash lightweight synthetics and heavyweight cottons separately, if possible, so that the loads dry more evenly.
7. Avoid creating dense, tightly packed loads, as this prevents proper tumbling action and airflow, dramatically increasing drying time.

Step 3: Clean exhaust ductwork  

1. Carefully detach the flexible metal exhaust duct from the dryer outlet so the full length can be inspected.
2. Support the ducting to avoid kinking.
3. Use a bright flashlight to look for any tears, rips, or perforations that could allow lint leakage.
4. Ensure all duct sections and elbow connections are properly overlapped and sealed.
5. Use the rigid copper duct brush attachment for your vacuum cleaner to scrub out lint deposits inside the duct.
6. Insert the vacuum hose with the brush from the dryer end through to the exterior vent hood outside.
7. Apply several back-and-forth strokes to loosen the stuck-on lint and pull it out.
8. Remove the outdoor vent hood cover and use a small wire brush to dislodge any packed lint surrounding the duct termination point.
9. Brush off the vent hood screen as well.
10. Resecure any connections that are loose or sagging.
11. Ensure the proper exhaust vent slope is 1⁄4 inch per foot.

Step 4: Clean and check the blower wheel

1. Disconnect power to the dryer before inspecting or cleaning the blower wheel.
2. Locate the large circular vent chamber on the back of the dryer where the blower wheel is housed.
3. Use a vacuum crevice tool to suck out any lint deposits surrounding the blower wheel inside the housing.
4. Carefully remove the blower wheel by detaching the retention nut in the center.
5. Use caution not to bend or distort the wheel fins.
6. Wipe the blower wheel thoroughly with a lint-free cloth.
7. Spin the wheel by hand to ensure it rotates freely with minimal friction or wobble.
8. Remove any lint caught on the motor mount or vent housing that may obstruct airflow.
9. Reinstall the cleaned blower wheel.
10. Test run the dryer and listen for any abnormal noises or rubbing that could indicate damage.

Step 5: Verify thermistor readings

1. Understand that NTC thermistors use changes in resistance based on the surrounding air temperature in the dryer drum and venting. At room temperature, the resistance of the outlet thermistor should be around 10,000 ohms. The thermistor near the heat source should measure around 25,000 Ohms.
2. Use a multimeter to take a resistance reading of the thermistor while heating it with a hair dryer..
3. Cross-reference the measured resistance against the temperature versus resistance curve chart specific to your thermistor, which can be found in repair manuals.
4. If the resistance and temperatures do not align with the chart, the thermistor is faulty and must be replaced.
5. Pay close attention to the thermistor readings during the early stages of a cycle when E13 errors are most likely to occur due to bad temperature readings.
6. A malfunctioning thermistor provides false temperature information to the control board, leading to issues.

Step 6: Verify clectrical connections

1. Inspect every wire harness connection on sensors, heating circuits, switches, and the control board.
2. Look for broken or loose plugs, as well as pins that are not fully seated in the connectors.
3. Wiggle the wire harnesses while the dryer is running to check for any intermittent connections.
4. Ensure all metal ground connections are tight and free of corrosion.
5. Check that the terminal block screws are torqued to the proper specifications.
6. Review the wiring diagrams to identify the circuits and junction points related to the dryer’s operation.
7. Faulty connections that cut in and out during a cycle will cause erratic heating and sensor responses, leading to over-drying.
8. Secure any loose plugs and replace any defective harness wiring.

Step 7: Replace control board

If you’ve verified all components have continuity and proper resistance, are visually intact, and wiring connections are sound, then the last remaining culprit may be a defective control board.

The relay circuits that energize the heating element may have shorted, or the programming timers may be malfunctioning. This causes abnormal cycle operation which leads to over-drying faults.

Before replacing the control, recheck that ventilation paths are clear, the exhaust system is functioning normally, and all plugs are firmly connected to their sockets.  

More Information

Thank you for reading! We hope this guide helped you get your dryer working again.

If you have any other appliance repair needs or projects, don’t hesitate to explore our other troubleshooting guides and videos. 

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