A water softening system for removing at least a portion of an ionic material contained in source water supplied from a water source and providing soft water, in which a smaller amount of the ionic material is contained than in the source water, to a source of demand, the water softening system comprising:
- filter units including a first filter unit and a second filter unit, each configured to remove at least a portion of the ionic material contained in the source water based on an electric force and to discharge the soft water;
- a supply passage including a first water introduction passage connected to the first filter unit for supplying the source water to the first filter unit, and a second water introduction passage connected to the second filter unit for supplying the source water to the second filter unit;
- a discharge passage including a first upstream side water exit passage connected to the first filter unit for discharging water from the first filter unit, and a second upstream side water exit passage connected to the second filter unit for discharging water from the second filter unit;
- a circulation passage connecting the discharge passage and the supply passage, including a first downstream side circulation passage connected to the first upstream side water exit passage, a second downstream side circulation passage connected to the second upstream side water exit passage, and a common circulation passage connected to the first water introduction passage, the second water introduction passage, the first downstream side circulation passage, and the second downstream side circulation passage;
- a filter management material provider disposed in the common circulation passage to provide a filter management material used to manage a performance of the filter units to water that flows along the circulation passage;
- a pump disposed in the common circulation passage to pump, together with the filter management material, the water that flows along the circulation passage to the filter units;
- a supply valve disposed in the supply passage to open and close the supply passage;
- a discharge valve disposed in the discharge passage to open and close the discharge passage;
- a first circulation valve disposed in the first downstream side circulation passage;
- a second circulation valve disposed in the second downstream side circulation passage;
- and
- a processor electrically connected to the filter units, the supply valve, the discharge valve, the first circulation valve, the second circulation valve and the pump;
- wherein the circulation passage is connected to one site of the supply passage, which is located on a downstream side of the supply valve with respect to a direction, in which the water flows in the supply passage, and one site of the discharge passage, which is located on an upstream side of the discharge valve with respect to a direction, in which the water flows in the discharge passage, and
- wherein the processor is configured to, in a filter management mode:
- control the supply valve and the discharge valve to be closed;
- control the first circulation valve and the second circulation valve to be opened;
- control an operation of the filter unit to be stopped;
- and
- control the pump to be operated.