either one will take awhile to heat, but electric takes longer, especially on mine.
Gas burners are favorite hangouts for cobwebs and the critters that make them. make sure the gas tube is clean and then see why the gas burner isn't igniting.
If you have a meter and know how to use it, you can shut power off and disconnect the wire on one side of the electric element. If you put your meter on Ohms and measure the resistance of the element, it should be ZERO. If it's infinity, then the element is shot (easy fix) but propane should still work.
Jim