HEAT PUMP DRYER TUB MOTOR IS LOCKED & CAN NOT TURN
Cause
For models that the tub motor also turns the blower motor. Defective Motor or no voltage to the motor. Foreign item in the blower such as a dryer sheet
Solution
Check motor connection and motor winding resistance and voltage to the motor.
Remove foreign item such as dryer sheet.
Cause
For models that the tub motor is turned by a rotor and stator. This could be a cracked magnet on the rotor or an open winding on the stator or no voltage to the stator
Solution
Check for tub moving freely by hand and if does not may be a bad tub bearing, cracked magnets on the rotor, stator windings resistance 10-20 ohms on all three windings, foreign item between tubs. Also physical damage on the cabinet touching the drum can cause this also.
DETAILS BELOW:
For the style of heat pump dryer that uses the BLDC motor to turn the tub belt and also the blower see below.
Check each motor winding for proper resistance range.
U to V = 10-20Ω ± 2Ω
V to W = 10-20Ω ± 2Ω
W to U = 10-20Ω ± 2Ω
Also check winding for 220 ~ 240 Volts ac.
All windings should measure within 1 ohm of each other. If any winding is out of range then replace the motor. If the main board does not produce voltage then replace the main board.
For the style of heat pump dryer that uses the rotor and stator to turn the drum see below.
Some newer models of heat pump dryers use a rotor and stator to drive the drum. This is similar to the washer rotor and stator but includes a gear case to couple the drum to the rotor.
See an example below of this layout taken from the exploded view for a heat pump condensing dryer from a wash tower.
If drum does not rotate in during cycle, spin drum by hand. Does drum make a noise?
If noise is present: Visually inspect the rotor and stator. Also check the cabint for physical damage.
- Remove cover. Is rotor bolt loose? If so, tighten rotor bolt when reassembling.
- Check Stator bolts. Are bolts loose? If so, tighten.
- Inspect rotor for cracked or broken? If so, replace rotor.
- Inspect stator harness for damage and if damaged replace the harness.
- If any of the above are not the issue then the issue could be the gear assembly.
If no noise:
Be sure the stator is getting voltage from the main board.
