A bottled water dispenser is disclosed that includes a water bottle, a cold tank, and an ozone generator, which is fluidly coupled to a Y-connector. The dispenser includes a first tube that is fluidly coupled to a first port of the Y-connector, with the first tube being configured to deliver ozone gas to the cold tank. The dispenser further includes a second tube that is fluidly coupled to a second port of the Y-connector, with the second tube being configured to deliver ozone gas to the water bottle. The ozone gas is effective to sterilize and prevent biofilm formation within the interior areas of the cold tank and water bottle. The dispensers further include an in-line flow restrictor positioned in-line with either the first tube or second tube, which helps balance the flow of ozone that is delivered to the cold tank and water bottle.