not heating running forever?

I have trouble with white film on my dishes, tried a descaler,lime remover made for washers that had a wax plug which is not supposed to be removed but placed in the utensil rack and should melt when dishwasher reaches 125 degrees, it didn't melt which leads me to believe that the heating element is not functioning properly. Also, the sanitized light doesn't illuminate any longer, probably also a good indicater that the temperature is not reaching what it is supposed to as it makes no difference which cycle I run it in---any suggestions on what needs to be replaced? It also runs and runs and runs to finish a cycle.