Filter
Replaces W10208631
Filters clog with use. The manual lists how often to change it.
Fuse
Replaces W10138793
Reads or limits temperature. A failed one can stop the heat or let it run too hot.
Capacitor
Replaces W10343300
A motor that hums but won't start often needs a new capacitor.
Magnetron
A motor that hums but won't turn, or stops once it's warm, needs replacing.
Magnetron thermostat
Reads or limits temperature. A failed one can stop the heat or let it run too hot.
Interlock
Door, lid and control switches stop a cycle when they fail.
1FilterW10208631A
2FuseW11707984
3CapacitorW10850446
4MagnetronW10754299Part numbers come from the Sears PartsDirect parts list for the Whirlpool WMH31017FB1 (view the list), checked November 15, 2026. Amazon buttons open a search for the part number; we may earn a commission.
Where the model number is
Open the door: the label is on the frame. Over-the-range models: sometimes behind the vent grille.