We have a Janitrol furnace model GMP100-3. We noticed it would sound like it was starting up but then would cut out. This would happen 5 - 6 times and then it might run ok for 10 minutes and then shut off, repeating the process again. We were told to turn the power off for 5 minutes to see if that worked - it didn't change anything, so we replaced the thermostadt. We figured out we installed the wrong thermostadt and several days later put in the correct thermostadt. Now we can get the blower to come on, but the igniter doesn't light, so the air blowing is cold. What else might we try before giving in and calling a technician?
I have a very similar issue with the same furnace. When I turn on the heat, the inducer blower goes on, then off, then on, and will sometimes eventually stay on. Although with mine, the furnace actually lights if the whole thing doesn't cut out, and once it's on, it stays on.