Water filter with strainer scraping means

A water filter comprising a housing, a strainer mounted inside said housing and defining said housing into an inner water chamber and an outer water chamber around said inner water chamber, a water intake valve adapted for guiding water into said housing, a water outlet adapted for guiding filtered water out of said housing, and a drain valve connected to said housing at a bottom side and adapted for carrying off waste water from said housing, wherein a reciprocating device is mounted on said housing at a top side and controlled by a pressure differential controller to reciprocate a disk-like scraper in said inner water chamber along an inside wall of said strainer, causing it to scrape out dirt from said strainer, said disk-like scraper comprising a center water hole, and a check valve mounted in said center water hole for permitting water to flow downwards in said inner water chamber through said center water hole and stopping water from flowing upwards in said inner water chamber through said center water hole.