In a solid-oxide fuel cell system, the electronic control unit which measures and controls temperatures, pressures, valve sequencing, valve positioning, blower power, electric output, and flows of air and fuel gas, is disposed in a "cool zone" within a structural housing. Electric leads from the control unit to the individual system components therefore do not pass through the housing. The few leads from the control unit required for connection of the fuel cell system to a load are gathered into a single electrical connector mounted through a wall of the structural enclosure.