Abstract: A method of converting an inverted bottle water dispensing system for use with an automatic bottle refill mechanism. The inverted bottle water dispensing system to which the method relates an open topped cooling reservoir with a mounting adaptor for receiving an inverted bottle water disposed on top of the reservoir. The automatic bottle refill mechanism to which the method relates has a conduit connected to the inverted water bottle and connected to a float valve positioned within the inverted water bottle. The conduit is connected to a pressurized water service so that a continuous replenishing supply of water is supplied as permitted by the float valve. The method includes the step of permanently securing across the open top of the cooling reservoir a rigid closure cap to which a bottom of the mounting adaptor has been permanently secured. The rigid closure cap has a single access opening in liquid communication with the bottom of the mounting adaptor.