High-limit thermostat
Controls the heat. A dryer that runs too hot or won't heat points here.
Drive belt
Replaces WE12X82
Turns the drum. If the motor hums and the drum stays still, check the belt first.
Drum glide bearing
Replaces WE1M333
Thumping or squealing during a cycle points to worn rollers, pulleys or bearings.
Blower wheel
Replaces WE16X17
Moves air through the drum. Long drying times and rattling point here.
Sleeve bearing
Replaces WE3X65
Thumping or squealing during a cycle points to worn rollers, pulleys or bearings.
Door switch
Replaces WE4M157
Door, lid and control switches stop a cycle when they fail.
1ThermostatWE4M137
2Drive beltWE12X10014
3Glide bearingWE03X37318
4Blower wheelWE16M15Part numbers come from the Sears PartsDirect parts list for the Hotpoint DLB3900SBM (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
Inside the door opening, on the frame or the back of the door. Older models: on the back panel near the cord.