My dishwasher heating coil does not heat up.?

I have a Hotpoint dishwasher model # KUDK01TKBL1 the water going into the diswasher is heated to 125+ deg and it drains at the end of the cycle, however it does not heat up to sanitize or dry. I thought it might be the heating element but I was told that the water would not drain if the heating element was bad and it was probably the thermostat. How do I determine what needs to be replaced.