Could be anything. Faulty control module, faulty wiring, faulty heater plate, faulty mains filter board or water leak. You will need to get someone out to find the fault. Yes, it probably will be expensive. F&P parts for dish drawers are pricey. If it was me I would get rid of it and wash by hand. No need for dishwashers in an average household. Dishwashers are for lazy people in my opinion.
George, October 2012