Patent ID: 7854607
Filing Date: 2010-12-21
Classification: F23N

Abstract:
1. A control for controlling the operation of a fuel-fired heating appliance, the control comprising: a CO sensor disposed on the control in the vicinity of the appliance so as to ensure that the sensor is capable of sensing the presence of carbon monoxide gas and providing an output that changes relative to changes in carbon monoxide level so as to be indicative of the level of carbon monoxide gas, wherein said sensor is subject to changes in output value due to the effects of humidity or general aging; a memory in which one or more previously sensed CO sensor output values are stored; and a processor that monitors the CO sensor and stores one or more previously sensed CO sensor output values in the memory, and responsively discontinues the operation of the appliance when the sensor output increases by more than a predetermined amount of at least 50 percent over at least one previously stored CO sensor output value in a predetermined time period of thirty minutes or less, such that the control is configured to overlook any drift in the output value of the sensor that might indicate an inaccurate level of carbon monoxide gas.