Whirlpool Microwave Error Code ERR B

ERR B means the control board is detecting no pulse signals from the weight sensor, or the sensor's signal frequency is below the required 4267 Hz minimum. The weight sensor is used by automatic and sensor-cook programs to detect the load on the cooking platform. When this signal is absent or too weak, the microwave displays ERR B to indicate the sensor system needs attention.

Unplugging the microwave for a few minutes may temporarily clear the display, but ERR B will return as soon as the control board checks the weight sensor again if the underlying fault is still present. A reset does not fix the sensor or wiring issue causing the code. Clearing the error requires diagnosing and repairing the actual fault.

Repair costs vary depending on the faulty component. Weight sensor replacement parts typically range from around $20 to $80, while a replacement control board can range from $80 to $200 or more. Adding professional labor, total repair costs generally fall between $100 and $350 depending on the diagnosis, parts required, and service rates in your area.

Some causes of ERR B are DIY-accessible, such as reseating a loose wire harness connector or inspecting terminals for corrosion. However, replacing the weight sensor or control board involves disassembling the microwave cabinet and working near high-voltage components, including the capacitor, which can hold a dangerous charge even when unplugged. Technicians with appliance repair experience can safely perform these repairs, but inexperienced users should have the work done professionally.

Basic microwave heating functions may still operate while ERR B is active, but any cooking mode that relies on the weight sensor, such as auto-cook or sensor-cook programs, will not function correctly or may be disabled entirely. Using the microwave in manual time-cook mode is generally not a safety hazard from the error itself, but leaving an underlying wiring or sensor fault unaddressed is not recommended long-term.