A filtration system for an appliance includes a water source coupled with the appliance to provide an intake water flow. A filter unit is coupled with water source to receive the intake water flow and dispense a filtered water flow. An isolation valve is coupled between the water source and the filter unit and movable between a first position and a second position. A distribution valve is coupled with an ice maker and a water dispenser of the appliance. The distribution valve receives the filtered water flow when the isolation valve is in the first position, and the distribution valve receives the intake water flow via a bypass line when the isolation valve is in the second position. The isolation valve is configured to move to the second position upon expiration of the service life of the filter unit.