Is this a flat-plate design, or is it a coiled heating element?
Sounds like a similar experience to what I tried for an electric heat source several years ago in my small GOSM gas cabinet smoker. I have an 800-watt hot plate that has a cast-iron disc, and thermal energy transfer efficiency is very low. Smoke chamber temp rise was only 20-30 degrees F. When set on high, the heating element cycled on/off rather slowly, and I came to the conclusion that the only way I would get enough heating potential form the flat disc plate would be to add a metal object that had fins for better transfer of the heat to air. The plate was very hot, but the heat was not being carried away and transferred to the air inside the smoke chamber.
If you could find something to set on top of the hot plate that will remove some of the heat from it, this will help, but may not be enough to generate the BTU's needed to get the smoker hot enough.
A coiled heating element will transfer heat to air much better by itself than the flat plate design will, and having the thermostat farther away from the heating element (removed from the assembly and placed in open air close to the element...requires some electrical wiring skills) would also help it get hotter before it switches off. To do this (modifying an electrical component) is not the best idea and should only be done with careful safety considerations.
Electric smoker replacement heating elements can be purchased from various sources, though I've looked for them in specific. The best way to start would be to have a matching thermostat control to go along with the smoker heating element.
Eric
