Help!!! My dishwasher had not been run fro a few weeks and when we ran it we got a burning smell (like burnt plastic or wiring smell) coming from the wash chamber. I opened the kick panel underneath and there is not smell or burnt components down there, and the pump runs fine. The heating coil does not have any fallen plastic or anything on it, but the coating on the element seems to be coming off (looks like rust) when I rub it. Do I need to replace the heater coil? Is there anything else I should check first?