Method and apparatus for sensing and regulating the temperature of a fluid is provided having means for generating a first signal whenever the actual temperature of the fluid whose temperature is to be regulated is lower than a preselected temperature level. The first signal has an amplitude proportional to the magnitude of the difference between the actual fluid temperature and the preselected temperature level. Means are provided for generating an output signal whenever the amplitude of a reference signal exceeds the amplitude of the first signal. Means are also provided for heating the fluid, the duration of said heating being proportional to the duration of said output signal.