A phase error circuit including phase difference logic and delay and register logic. An applicator device is provided that has a curved first wall, a curved second wall, and a horizontal shelf that joins the first wall to the second wall. The level determining circuit outputs an adjusting signal according to a reference voltage range corresponding to a minimum voltage level of the coupling signal within a predetermined time period. The controller causes the flow-rate regulating valve to continue the regulation at least until it is not necessary to increase the pressure in the heat exchanger, and then terminates the regulation. These bleed bypass passageways are relatively restrictive to liquid flow so as not to undermine system pressure or otherwise undermine fuel supply to the fuel injectors.