If the water level light is staying on, then working the microswitch back and forth a few times may help. If there is still a problem, you may need to replace the thermostats. They are pretty cheap and easy to repair.
James Scott, August 2010
If you have emptied the water container and the full light is still on then the microswitch hasn't reset. To reset this switch take off the top lid, then the side panel on the right hand side (make sure electric is switched off). Put your hand underneath the motor where the microswitch arm is located and push down several times. This should reset the water container full condition.
