A liquid heating appliance includes a container defining a liquid heating compartment, a lid for covering the container, and a heater for heating liquid within the compartment. The lid defines a recessed receiving chamber for receiving a volume of liquid, and the receiving chamber includes a non-return filling valve. In a filling mode of the appliance, the filling valve allows liquid to flow from the receiving chamber into the liquid heating compartment. In a heating mode of the appliance, the filling valve prevents fluid from flowing from the liquid heating compartment into the receiving chamber.

In a portable container system for heating a beverage generally, the system includes a container for containing a beverage to be heated. The container generally has a bottom and a side wall together defining an internal reservoir containing the beverage to be heated. A base of the system is operable to heat the container at the bottom thereof. The base is constructed of multiple layers generally including at least a top barrier layer, an electrically non-conductive bottom barrier layer and a thin film heating element intermediate the top barrier layer and the bottom barrier layer.