JET BATH PUMP WITH FILTER

PURPOSE:To improve ease of handling by arranging a control section to drive a pump and a three-way valve so that a back washing of a filter is performed at least once to accomplish a backwashing of a filter medium of the filter automatically with clean water. CONSTITUTION:When a bath tub 1 is filled with water and electrodes 23 and 23 of a water level sensor 6 submerges, a current flows through the water and a Dc voltage rectified and smoothed with a rectifier 19 and a capacitor 22 is inputted into an input P0 of a microcomputer 15 to be converted into analog from digital, which allows the detection of water filling the bath tub 1. When the water level of the bath tub 1 reaches a specified value, it is judged whether or not the water reaches the specified level first. If it reaches the level first, a pump drive signal and a three-way valve drive signal are outputted from outputs P2 and P3 of the microcomputer 15 to start a pump 5 while the three-way valves 7 and 7 are switched over to a backwashing position to perform a backwashing of a filter 9. Thereafter, when one minute passes, the pump 5 is stopped while the three-way valves 7 and 7 are switched over to the positions of jetting bubbles and filtration in circulation to stop the backwashing operation. This enables the backwashing of a filter medium of the filter automatically with clean water thereby improving ease of handling.