Patent ID: 8430666

Claim:
A low pressure liquid fueled heater having a control system, comprising: a fuel nozzle; a combustion chamber operably positioned to receive output from said fuel nozzle; an optical sensor operably positioned to view within said combustion chamber; wherein characteristics of said optical sensor vary in response to changes in a flame that may be present within said combustion chamber; a control in electrical communication with said optical sensor; wherein said control determines an average optical sensor value during each of a plurality of brief sampling periods; wherein said average optical sensor value is calculated from a plurality of readings received from said optical sensor during each of said brief sampling periods; and wherein said control determines a reference point average that is an average of a plurality of previously determined said average optical sensor value; wherein said control alters at least one characteristic of said low pressure liquid fueled heater if the absolute difference between said recently determined average optical sensor value and said reference point average is greater than a predetermined reference limit, thereby indicating an abrupt change; and a solenoid valve in communication with said fuel nozzle, wherein said control causes said solenoid valve to be adjusted when the absolute difference between said recently determined average optical sensor value and said reference point average is greater than said predetermined reference.