We have a Kenmore gas counter flow furnace, 75,000 BTU the ignitor clicks and tries to light, sometimes it works perfect, other times it takes three or four attempts. Gas company has been out 4 times this week, because the problem is intermittent, they are telling us to replace the furnace. Example: sometimes if you put the outside door panel on, the ignitor clicks but will not light, remove the front door and the pilot lights. Other times it will light perfect with the door on. The ignitor has been replaced, the Gas company wants to replace the pilot, but we found out it is no longer made. The gas pressure coming into the furnace/house has been tested, it is good. The model number of the furnace is 867.768070. Any help/suggestions would be GREATLY appreciated!

I would first check for loose wires especially ground wires in your furnace. Also if the blower door has a safety switch I would check it also. Intermittent problems are the most difficult.

You might post a picture of the ignitor. Sears never made a furnace they always buy from some other company and put there name on it so it might still ba available.