A combustion-heating system comprising: a plurality of combustion heaters connected to each other, a combustion heater including: a heating plate; an arrangement plate disposed facing to the heating plate; an annular outer peripheral wall disposed between the heating plate and the arrangement plate; a partition plate disposed between the heating plate and the arrangement plate; a combustion chamber positioned along the outer peripheral wall, the combustion chamber in which fuel gas collides with a flame-holding part constituting part of the outer peripheral wall, thereby holding flames; an inflow path in which sidewalls thereof are constituted by the arrangement plate and the partition plate, the inflow path through which the fuel gas flows into the combustion chamber; and an outflow path in which sidewalls thereof are constituted by the heating plate and the partition plate, the outflow path through which exhaust gas flows from the combustion chamber toward the outside thereof, the outflow path to preheat the fuel gas by heat of the exhaust gas through the partition plate; and wherein a communication path is disposed at a connection part between the plurality of combustion heaters, the communication path communicating combustion chambers thereof with each other, the flame-holding part and the communication path are provided in series in a direction perpendicular to the heating plate. a plurality of combustion heaters connected to each other, a combustion heater including: a heating plate; an arrangement plate disposed facing to the heating plate; an annular outer peripheral wall disposed between the heating plate and the arrangement plate; a partition plate disposed between the heating plate and the arrangement plate; a combustion chamber positioned along the outer peripheral wall, the combustion chamber in which fuel gas collides with a flame-holding part constituting part of the outer peripheral wall, thereby holding flames; an inflow path in which sidewalls thereof are constituted by the arrangement plate and the partition plate, the inflow path through which the fuel gas flows into the combustion chamber; and an outflow path in which sidewalls thereof are constituted by the heating plate and the partition plate, the outflow path through which exhaust gas flows from the combustion chamber toward the outside thereof, the outflow path to preheat the fuel gas by heat of the exhaust gas through the partition plate; and a heating plate; an arrangement plate disposed facing to the heating plate; an annular outer peripheral wall disposed between the heating plate and the arrangement plate; a partition plate disposed between the heating plate and the arrangement plate; a combustion chamber positioned along the outer peripheral wall, the combustion chamber in which fuel gas collides with a flame-holding part constituting part of the outer peripheral wall, thereby holding flames; an inflow path in which sidewalls thereof are constituted by the arrangement plate and the partition plate, the inflow path through which the fuel gas flows into the combustion chamber; and an outflow path in which sidewalls thereof are constituted by the heating plate and the partition plate, the outflow path through which exhaust gas flows from the combustion chamber toward the outside thereof, the outflow path to preheat the fuel gas by heat of the exhaust gas through the partition plate; and wherein a communication path is disposed at a connection part between the plurality of combustion heaters, the communication path communicating combustion chambers thereof with each other, the flame-holding part and the communication path are provided in series in a direction perpendicular to the heating plate.