Not trying to steal Shannon's thunder or anything but I have the EXACT same problem except we have not replaced anything like she (or he!) has. We moved in a few months ago and it has always done the really short cycles until it eventually stays on. The burner stays lit the whole time, just the blow...

Thanks for the replies! I ended up calling a tech to come out and take a look. Apparently there are two 3 amp fuses..I thought there was just the one and didn't check the other.. so a $1 fuse ended up costing me $66 but oh well, gotta have heat!

I put in a new upper limit switch about two weeks ago and I have pushed the button on it, still no change. :-/

Our natural gas furnace has been running ok so far this season until the other day(besides the very annoying constant short cycles--the burner stays lit but the fan will run for 10 or 20 seconds, then cut off...back on...off... then eventually stay on to heat the house). The whole unit now does noth...