Bosch Dryer Error Code E:28

E:28 on a Bosch dryer indicates an NTC thermistor error, specifically a break or short circuit in the temperature sensor or its wiring. The NTC is a resistor that the control board uses to monitor drum or exhaust temperature. When the board detects an invalid resistance reading, it triggers E:28 and may stop the cycle. The fault points to the sensor itself, the connecting cables, or the terminal connectors.

It is not recommended to continue operating the dryer while E:28 is active. The NTC is a key safety component that tells the dryer when temperatures are reaching unsafe levels. Without reliable temperature feedback, the dryer cannot regulate heat properly, which creates a potential overheating or fire risk. Stop using the dryer until the fault is diagnosed and corrected.

A power reset, such as unplugging the dryer for a few minutes and restarting it, may temporarily clear the E:28 display, but the error will return if the underlying fault is still present. The code is generated because the control board is detecting a real electrical problem with the NTC circuit. A reset does not repair a broken wire, corroded connector, or failed sensor. Proper diagnosis and repair of the root cause are required to permanently resolve the fault.

A knowledgeable DIYer can often resolve E:28 by inspecting and reseating the wiring harness connectors or replacing the NTC thermistor, which is a relatively straightforward repair. You will need a multimeter to test the sensor and cables. If the wiring is damaged or the NTC reads open or shorted, replacing the faulty component should clear the error. If the fault persists after replacing the sensor and checking all wiring, the control board may need professional evaluation.

If the repair requires only a new NTC thermistor, the part itself typically costs in the range of $15 to $50 depending on the specific model. If a technician is needed, total repair costs including labor generally fall in the range of $80 to $200. Wiring harness repairs or connector replacement are usually on the lower end of that range, while control board replacement would be significantly more expensive.