Bosch Washer Error Code F:20

F:20 indicates that the washer detected heating activity from the heating element during a period in the wash cycle when heating was not supposed to occur. The control system monitors heater operation continuously and flags any activation outside the programmed heating windows. The most common causes are a stuck heater relay on the power module, a faulty NTC temperature sensor, or a defective heating element. The machine stops operation to prevent potential overheating damage.

A reset can clear the error if the fault was caused by a temporary control glitch rather than a hardware failure. Turn the washer off, wait at least one minute, and turn it back on. If the F:20 code reappears during the next cycle, the underlying cause is a physical component issue such as a stuck relay, faulty NTC, or defective heater element that requires proper diagnosis and repair.

Repair costs depend on which component is at fault. An NTC temperature sensor is generally an inexpensive part, with replacement typically ranging from around 50 to 120 dollars including labor. A new heating element repair can range from approximately 100 to 200 dollars. If the power module requires replacement, costs are higher and can range from roughly 200 to 450 dollars or more depending on the model and labor rates in your area.

The first step you can take yourself is a full power reset by turning the washer off, waiting a minute, and turning it back on. If the error clears and does not return, no further action may be needed. However, if the code comes back, diagnosing and replacing the NTC sensor, heater element, or power module involves working inside the machine with electrical components, which is best handled by a qualified technician.

You should not continue using the washer while the F:20 fault is active. The error indicates the heating element may be receiving power at unintended times, which creates a risk of overheating the water or the machine itself. The washer typically halts operation when this code is triggered specifically to protect against these conditions, and running it before the fault is resolved is not advisable.