I have a heil model # NULE075AG01 I replaced the ignator a few months back because it was bad, but the new problem is after it runs for a while and heats up the house it shuts off like it should and when it's time to come back on you can hear the blower motor running but there's no heat, I can look in the furnace and see the red light blinking constantly. I can remove the bottom panel and leave it off for about 5 minutes or so and replace the panel and it will start working again like it should. This is installed in the house in it's own closet with proper ventelation.Sometimes it will work fine all day and then it starts acting up again. This was an LP heater and in 1993 it was converted to natural gas.
Any suggestions on what I need to look for? Thanks.