If you take the wires completely off your thermostat and tie the wire from the r terminal to the wire from the w terminal the furnace should run until you seperate these wires if it does not then you will have a problem with your furnace if it works fine then your controller is malfunctioning and you need to replace it, if the problem is with the furnace email me at
mike@howtorepairairconditioners.com and I will walk you through it