Amana Microwave Error Code FH

The FH code on an Amana microwave means the control board has detected high current from the magnetron circuit. The magnetron is the component that generates microwave energy to cook food, and it operates within a high-voltage circuit. When current in that circuit exceeds expected levels, the microwave shuts down and displays FH as a protective measure. Diagnosing this code requires Service Test mode and a check of the magnetron and current sense loop wiring.

You should not continue using the microwave while the FH code is active. The code indicates a high-current condition in the magnetron circuit, which can involve components operating at potentially lethal voltages. Continued use risks further damage to the appliance and poses a safety hazard. The microwave should remain unplugged until the fault is diagnosed and repaired by a qualified technician.

The technician begins by placing the microwave in Service Test mode and running the magnetron test to isolate the fault within the magnetron circuit. They also verify that the wire associated with the current sense circuit is correctly routed through the current sense loop, since improper routing can trigger a false FH reading. If both of those checks are normal, the high-voltage diode, capacitor, and wiring are inspected for damage. All high-voltage component work requires the capacitor to be safely discharged before hands-on testing.

Unplugging the microwave and restoring power may temporarily clear the FH code, but the fault will almost certainly return during the next heating cycle if the underlying problem is not resolved. A reset does not correct a failing magnetron or an incorrectly routed sense wire. Proper diagnosis using the magnetron test in Service Test mode is needed to prevent the code from reappearing.

Repair costs depend on the root cause identified during diagnosis. A magnetron replacement is typically the most expensive repair, with parts and labor costs often ranging from $150 to $350 or more depending on the model and service provider. Repairs involving only a wiring correction or a less expensive component such as a diode are generally on the lower end of the cost range. In some cases, the cost of repair may approach the cost of replacement, so obtaining a diagnosis first is advisable.