I have an electric dryer that does not dry well. The heating element comes on and off. The exhaust is not blocked.

The element should cycle on and off, but perhaps the high limit thermostat is opening too soon.

Also, the blower could be obstructed or slipping. There could be lint inside the unit that is causing an obstruction, as well.

Having determined there is no obstructions, blower wheel not slipping or damaged, and belt not slipping, damaged or frayed. Replace high limit thermostat.

Regards,
Stew