A thermally sensitive control for a liquid boiling vessel having first heating means for boiling liquid in the vessel and second heating means for maintaining boiling or keeping liquid in the vessel warm after it has boiled comprises a boiling-sensitive actuator (232), a manually operable control member (204) movable from an "on" position in response to operation of said actuator to open a first set of contacts (212) to switch heating from said first heating means to said second heating means and means (228, 240) operable upon the vessel being lifted from a support surface to open a second set of contacts (214) so as to switch off both heating means, said respective sets of contacts only being recloseable thereafter by replacing the vessel upon its support surface and manually returning said control member (204) to its "on" position.
