[pmsage]

Electric dryer will not stay on. press the start button drum begins to turn but as soon as you release the start button it stops. If I hold the button it continues to run unitl I release it. I replaced the start button and still the same effect. Door switch is ok. What to do next ?

[denman]

Here are your parts
Parts for GE WSM2420D3WW Washer Dryer Combo - AppliancePartsPros.com

It is a GE so I cannot get a wiring diagram for it so cannot give specific help on this unit. GE likes to keep all tech info a secret.

On the motor there are 2 centrifugal switches.
They are activated when the motor gets close to operating speed.
One is for the heating element. This ensures that there is air flow before the heater comes on.
The other has two purposes.
It removes the motor's start winding. Leaving the start winding in circuit would overheat the motor.
Also it provides a a parallel circuit path around the start switch. This allows you to release the start button and the unit motor stays on.

If you hold the start switch for a while and there is no heat, then odds are that the centrifugal mechanism in the motor is not working. May be something as simple as the motor being clogged solid with lint or at worst the motor needs replacing.

If there is heat then check the connections at the motoer. It may also be a bad switch.
You cannot just replace the switches so have to replace the motor.