Patent ID: 6925999
Filing Date: 2005-08-09
Classification: F23N

Abstract:
1. A method for controlling operation of a heating system, said heating system including a furnace operable to provide heat to an enclosed space at plural heating rates, a controller for controlling operation of said furnace at selected ones of said plural heating rates, a thermostat for sensing the temperature in an enclosed space being heated by said furnace and for providing a signal or signals to said controller to call for heat at furnace heating rates less than the number of stages of heating rates of which said furnace is capable, and a sensor for sensing air returning from said enclosed space to said furnace for heating thereby, said method comprising the steps of: energizing said furnace at a first heating rate in response to a signal from said thermostat; sensing the return air temperature with said sensor; determining at least one of the return air temperature and the rate of return air temperature change versus time; and changing the heating rate of said furnace if said one of return air temperature and rate of change of return air temperature is one of less than and greater than a predetermined amount.