[Steve B]

When start button is pushed, dryer drum and fan come on but will only stay on while button is depressed. There is also no heat.

[kayakcrzy]

It is most likely going to be your motor, because the switch is momentery, and it is very well possible, that the motor will not get off the start winding to get to the run winding. I would doubt it would be the timer. This problem is something that I have expieienced numerous times. As for the heat not working, that could be because with the motor not going into the run cycle, it is not sending power to the elements. If you need me, you can reach me at web site at ApplianceEducator.com Tom

[denman]

I agree with kayak in part

I do not think the start switch is a momentary switch
I do think it is motor related

Steve B here is how this part of your dryer works
The motor has two centrifugal switches on it, they switch when the motor reaches operating speed

One switch is for the Run and Start windings of the motor
At rest the Run and Start are in circuit
At operating speed it switches out the Start winding and switches in an circuit path which is in parallel with the start switch
In other words keeps the motor running after you release the start switch

The other switch is for heat
At rest it is open
At operating speed it switches in current to your heaters
This is a safety device to ensure you only have heat when the motor/blower is running

I would open up the unit and take a look at them
If you are lucky you might be able to see the mechanism that switches them over and perhaps repair it. Check in the bottom of the dryer for a small spring
Often they are part of the motor assembly so it may cost a new motor to repair them