I have a comfortmaker rpj2 warm air furnace (gas) is R921500600 a good model #? also looking to find out the temp rating for high limit switch and part #. also door safety switch part #. I got a part # ***** Z-19-R921500600- 23CMW from some company is this the right door safety switch? i am gettin 4 flashes saying out on high limit what is the problem? the part # ***** the high limit is 1820-552 or 1320-552 is this a good part #? How do you reset control when out on high limit?it is a horizontal unit in the attic.