Dishwasher - frigidaire ultra quiet III

[OleGoat]

The dishwasher started taking 2-3 hours to complete a wash. After a little trouble shooting. I suspect either a heating element prob. or a cotroller/timer issue. This unit has a hi temp wash and a hi temp rinse option. When those options are not selected the wsah times are long but more normal. When using the "plate warmer" option the heating element remains cool to the touch. Any ideas?
Is the heating a homeowner fix or do you need a technician?
Any ideas appreciated.

[HayZee518]

The seals pass through the shell of the dishwasher. I suppose if you're very careful you could install the elements. Put the element in the clips provided and watch those silicone washers.