System and method of controlling condensing and non-condensing boiler firing rates

A control system for use in controlling operation of a hydronic heating system, comprising:

• one or more memory devices configured to store each of a first proportional-integral-derivative (PID) control program, a second PID control program, and first information setting forth a relationship between outside air temperatures and setpoint temperatures;
• and
• one or more control devices connected at least indirectly with the one or more memory devices and configured to operate to determine, at least indirectly, one or more signals configured to govern firing rates for at least one condensing boiler and at least one non-condensing boiler,
• wherein a first of the signals configured to govern a first of the firing rates for the at least one condensing boiler is determined in accordance with the first PID control program, and a second of the signals configured to govern a second of the firing rates for the at least one non-condensing boiler is determined in accordance with the second PID control program, and
• wherein at least one input value for use by one or both of the first and second PID control programs is a setpoint temperature determined based upon the information.

A method for operating a controller of a hydronic heating system having at least one condensing boiler and at least one non-condensing boiler, comprising:

• receiving an outdoor air temperature value;
• determining a temperature setpoint value based at least indirectly upon the outdoor air temperature value;
• additionally receiving a water temperature value associated with a location within the hydronic heating system;
• executing at least one proportional-integral-derivative (PID) control program so as to determine at least one output signal configured for governing at least one firing rate of one or more of the at least one condensing boiler and at least one non-condensing boiler based at least indirectly upon the temperature setpoint value and the water temperature value,
• wherein if a first condition is satisfied, the at least one PID control program includes a first PID control program dedicated to controlling only the at least one condensing boiler,
• wherein if a second condition is satisfied, the at least one PID control program includes a second PID control program dedicated to controlling only the at least one non-condensing boiler, and
• wherein if a third condition is satisfied, the at least one PID control program includes both the first and second PID control programs;
• and
• governing the at least one firing rate of one or more of the at least one condensing boiler and the at least one non-condensing boiler based upon the at least one output signal.