Sound like the rear tank float switch is stuck, this is located under the drum and is very difficult to get to, try refilling the water tank from the hot tap and put the tank back into the machine so that it connects back to the rear tank and shaking the dryer from side to side to try to loosen the float in the rear tank, then remove the tank and empty the water out and see if it has freed the float.
E Lambert, July 2004