Davis Rules (1991)

Dwight Davis, a widower and grade-school principal, is raising three sons with help from his wacky father Gunny. After the series moved from ABC to CBS, the oldest son and his friend were dropped (it was explained that the oldest son had become a foreign-exchange student) and Dwight's sister was added. Also off the show was Dwight's love interest Cosmo, who left to join a convent; added to the cast was Skinner, son of Dwight's college pals who are now psychologists working in Latin America. Appearing occasionally was Dwight's love interest Erika.