Patent ID: 7658335

Claim:
A hydronic heating system, comprising: a condensing boiler having condensing operating characteristics; a non-condensing boiler having non-condensing operating characteristics; a sensor measuring an outdoor air temperature associated with the hydronic heating system and providing an output indicative of the measured outdoor air temperature; and a controller, which includes a processor, operably coupled to the condensing boiler and the non-condensing boiler, the controller configured for calculating a heating load and for independently operating the condensing boiler and the non-condensing boiler in a manner that matches the heating load to at least one of the condensing operating characteristics and the non-condensing operating characteristics, wherein the controller, responsive to the sensor output being greater than a temperature switch point, initially enables the condensing boiler prior to an enabling of the non-condensing boiler by the controller, and wherein the controller, responsive to the sensor output being less than the temperature switch point, initially enables the non-condensing boiler prior to an enabling of the condensing boiler by the controller.