GE Refrigerator Error Code B

Error code B means the main control board detected a failure in its internal amplifier circuit during a thermistor test. The board tested its own ability to read the thermistor signal and determined the amplifier is bad. The fault is in the control board itself, not necessarily the thermistor sensor.

No, continued use is risky. Because the amplifier on the main control board cannot accurately process the thermistor signal, the refrigerator may lose the ability to regulate its temperature properly. Food stored in a refrigerator that cannot maintain 40 degrees Fahrenheit or below can spoil or become unsafe. Move perishables to another refrigerator or cooler while you arrange the repair.

The thermistor sensor itself is not the root cause of code B. GE's diagnostic specifically identifies the amplifier on the main control board as the failed component. However, a shorted thermistor or damaged wiring harness could have stressed or damaged the amplifier over time. After replacing the main control board, inspect the thermistor and its wiring to confirm they are in good condition before assuming the repair is complete.

The fix for code B is replacing the main control board. Before ordering a board, inspect the thermistor wiring harness for any obvious shorts, damage, or corrosion that could have caused the amplifier to fail. If the wiring looks intact, replace the main control board with the correct part number for your GE model. This repair is within reach for a confident DIYer comfortable working with appliance electronics, but if you are unsure about handling control boards, a technician can complete it in under an hour.

A replacement GE main control board typically costs between $100 and $300 depending on the model, with some boards priced higher for newer units. If you hire a technician, expect an additional $100 to $200 in labor, bringing the total repair to roughly $200 to $500. DIY replacement is feasible and can save the labor cost since the repair mainly involves disconnecting wire harnesses and swapping the board.