Gas and Oil Home Heating Furnaces - ducane mpg10084 furnace blowing cold

The furnace is about 7 years old and is sporatically not lighting.(it happened maybe 4 times last year, but has already happened twice this week)
The blower blows, the pilot light is lit...Just no main burner lighting. To resolve, I flip the red emergency off switch, wait about 10 seconds and flip it back on. Works every time, except the time between "outages" seems to be getting smaller. Waking up to a 50 degree house is getting kinda old. Anybody have any suggestions? Thanks in advance.

I am assuming this is a gas furnace, has hot surface ignition( something that turns cherry red) and the burners light off after the HSI turns red for 10-15 secs. If this is what you have clean the flame sensor. It's a rod that hangs down in front of the burners. Usually, HSI on the right side of the burners and flame sensor on the left side. clean with steel wool or emory cloth.

Thanks for the quick response. It is a gas furnace, and has HSI i beleive. (2 small "prongs" that glow for 5-10 seconds, which light the pilot?) Once the pilot lights, the main burners kick in a few seconds later.
I found 2 sensor looking devices, one on the right above the main burners, and one on the left below the burners. The arent rods per se, though. They each have 2 connectors on the back, and the front sort of look like a watch battery. (the actual metal sensor part is only about 1/4 inch thick and maybe 1/2 inch wide or so) Are those the flame sensors possibly?

I'm not really certain what you are describing. If you could post a picture that would help. Unless someone else has more experience with Ducane than than I do.