Abstract: Apparatus is provided for thawing frozen pipes or for cleaning pipes, for use with a source of warm thawing water or cleaning water, a source of compressed air, and a flexible tube suitable for being inserted into the end of a pipe through guide means to feed the water into the pipe while the tube is being advanced into the pipe. The apparatus comprises a valved water conduit having an inlet for connection to the source of water and an outlet for connection to the flexible tube, this conduit having a movable valve. A compressed air powered drive, usually a rotator, connectable to said source of compressed air, is arranged to move the valve in such manner as to continually interrupt the flow of water in the conduit and so to produce a pulsating flow of water in the tube for thawing ice in the frozen pipe or cleaning the pipe. The rotator for the valve may be a compressed air driven ratchet drive. A valve may also be provided for injecting air into the pipe to clear out ice or dirt.