GE Microwave Error Code Abnormal High Temp

The Abnormal High Temp error means the oven cavity temperature rose above the programmed set temperature and stayed elevated for more than 30 minutes during a bake cycle. The microwave's control system detected this as a runaway heating condition and stopped operation to prevent damage. The fault points to the thermistor assembly, convection heater TCO, relay board, or the convection heater itself as the likely source.

No, you should not continue using the microwave until the fault is diagnosed and resolved. This error indicates the oven exceeded its target temperature for an extended period, which points to a component that may be operating outside its safe range. Continued use could cause further damage to internal components or create a safety hazard.

Repair costs depend on which component has failed. A thermistor assembly or TCO tends to be a lower-cost part, while a relay board replacement typically costs more for both the part and labor. In general, you can expect diagnostics and repair to range from around 100 dollars to 300 dollars or more depending on parts needed and local labor rates. If the unit is older, it may be worth comparing the repair estimate against the cost of replacement.

Some diagnostic steps, such as checking for blocked vents or resetting the unit, are safe for a homeowner to perform. However, testing components like the thermistor resistance, relay board contacts, and TCO continuity requires a multimeter and familiarity with appliance electrical systems. Replacing internal parts like the relay board or thermistor assembly is best handled by a technician if you are not comfortable working inside a microwave, since the high-voltage capacitor inside can retain a dangerous charge even when unplugged.

Unplugging the microwave for a few minutes and restoring power may temporarily clear the error code, but it will return if the underlying component fault is not repaired. If the thermistor is reading incorrectly, the relay is stuck, or the heater is not cycling properly, the conditions that caused the fault will repeat. A reset is useful for confirming whether the error is intermittent, but it is not a fix.