Abstract: The present invention provides an on-demand liquid cooling/heating system, comprising: a liquid outlet for dispensing liquid to a user; a conduit system for flow communication between a liquid reservoir and the liquid outlet; a temperature control device disposed in the conduit system for controlling the temperature of liquid flowing therethrough, and comprising a thermoelectric temperature control device linked to an electric power source and to a control module for controlling the operation of the temperature control device; and a sensor for sensing liquid demand and for activating the temperature control module upon sensing a demand.