Your thermostat tells the furnace to provide your home with warm air. First, the carbon monoxide fan begins, then the furnace circuit board receives a signal from a switch that indicates to continue starting your furnace. The heating sequence takes a little time because several saftey switches are being used along with each furnace heat… Read more
Your furnace has several carbon monoxide safety switches that cause the heating to stop working. If the furnace door is off the unit, then this could be a reason the heating wont run. A bad fan or rusted inducer draft motor will let the furnace circuit board know that carbon monoxide will not be removed… Read more