Bosch Dishwasher Error Code Test (overheat)

The Test (overheat) code indicates that the dishwasher detected an overheating condition caused by a faulty control module. The control module failed to cut power to the heating element at the correct point in the cycle, allowing temperatures to rise beyond safe limits. This is a control board fault, not necessarily a heater fault, and requires voltage testing at the heater to confirm the diagnosis.

No, you should not continue using the dishwasher while this error is active. An uncontrolled heating element can cause internal components to warp or melt, degrade door seals, and in serious cases create a fire hazard. The appliance should remain off until the faulty control module is diagnosed and replaced.

Repair costs depend on the specific part needed and local labor rates, but control module replacement typically falls in the range of $150 to $400 or more when factoring in both the part and professional labor. Diagnostic fees from a technician may apply separately. Getting a quote before authorizing repairs is advisable, particularly on older units where the repair cost may approach the value of the appliance.

A knowledgeable DIYer can perform the key diagnostic step, which is checking whether voltage is present at the heater during a phase when the heater should be off. If voltage is confirmed present at that time, the control module must be replaced. Control module replacement requires comfort working with electrical components and disconnecting wiring harnesses, so those unfamiliar with appliance electronics should consider hiring a technician.

A reset may temporarily clear the fault code, but it will not resolve the underlying problem. If the control module is defective and causing uncontrolled heater activation, the overheat condition will recur as soon as the dishwasher runs another cycle. The fault requires component-level repair, not just a reset.