I have found that if a person's shower is interrupted by an event, such as a new baby, celebration of a promotion, placing groceries on the table (everyone except elders drops what they are doing to run and put away/peek at the groceries), they will run out of the shower to attend to the event and it sometimes does not shut off. However, if you put someone (not necessarily the same person) into the shower while it is running with no one in it, they will then take their shower and it shuts off normally.