A solid polymer type fuel cell system according to the present invention has a heat source of exhaust fluid from an electricity generation unit 23 in condensed heat exchangers 38, 40 in a heat recovery unit 19 and supply water from a water supply unit 66 as a heat source to be heated to a hot water through heat-exchanging process. In this way, the external agent may control tap settings of an equalizer based on feedback information from the receiver responsive to a data pattern generated and transmitted by the transmitter. A valve element is slidably mounted in the vertical drain pipe adjacent the second port and is movable between a lower position to close the second port to fluid flow, and an upper position which will open the second fluid port to fluid flow.