I have the Armstrong Ultra SX-80 furnace. The blower runs, but it's just blowing cold air. Checked thermistat and the batteries were low in it so I replaced them. Filter was not very clean, and air was still blowing out the vents at full force, but I changed it anyway. Still no flame. Is there a pilot on this furnace? If so, how do I locate it and re-light it if necessary?

I shut off my gas to my Armstrong ultra sx80 furnace now it won't light the thermostat is working with a jumper wire the fan works but seams like no gas is coming true help