A wood material board hot-pressing system with a primary circuit includes a supply pipe for discharging of hot heat transfer fluid from a heat generator and a return pipe for supplying cooled heat transfer fluid to the heat generator. A secondary circuit features a pressing device for pressing wood material boards. A supply channel supplies heat transfer fluid to the pressing device and a return channel returns cooled heat transfer fluid to the primary circuit. A controlling device contains a control valve and is configured to control a flow of heat transfer fluid from the primary circuit to the secondary circuit. A secondary circulation pump with variable output is set up to circulate the heat transfer fluid in the secondary circuit. The controlling device features a heat output recording device and is configured to automatically control a level of heat output (P) supplied to the pressing device.