Bosch Dryer Error Code 4

Error code 4 on a Bosch dryer indicates an overheating condition. The Extra Dry LED flashes in the progress indicator while the dryer monitors whether the temperature drops below the safety limit. If the temperature does not come down within 10 intervals of 30 seconds each, the dryer automatically stops the cycle to prevent damage.

No, you should not continue running the dryer while the overheating fault is active. The dryer automatically terminates the cycle as a safety measure, and bypassing or repeatedly resetting without resolving the root cause risks damage to the appliance and could pose a fire hazard. Resolve the underlying airflow restriction or component fault before resuming use.

If the fix is simply cleaning the lint filter and clearing a blocked duct, there is no parts cost involved. If a component like a thermostat, temperature limiter, or exhaust fan motor needs replacement, parts and labor together typically range from around $100 to $300 or more depending on the specific component and your location. Getting a diagnostic inspection from a qualified technician can help confirm which parts are actually needed before committing to repairs.

Start by removing and thoroughly cleaning the fluff filter, then inspect the exhaust duct and air-intake passages for any blockages or kinks. Make sure the exterior vent flap is opening freely and that the dryer has adequate clearance for intake air. If the error returns after clearing all airflow restrictions, a component such as a thermostat, temperature limiter, or exhaust fan motor may need to be tested and replaced.

A reset may clear the displayed fault and allow the dryer to restart, but the error code 4 will return if the underlying cause has not been addressed. The overheating condition is tied to actual temperature readings inside the machine, so fixing the airflow restriction or faulty component is necessary for a lasting resolution.