I have a Heil Gas Furnace Ultimate II that had a problem with a faulty high limit switch. I've replaced the switch with a new replacement (L300F Supco Manual Reset Limit Switch SRL300) and it worked fine for a while. But recently I've noticed that the high limit switch will occasionally get triggered, resulting in cold air being blown out until we reset the switch. I've also noticed that the piece holding the high limit switch gets very hot from the flame, but I'm not sure if this is by design or not and whether this is somehow triggering the high limit switch. I'm not really sure what is causing this and would appreciate any suggestions or assistance. Thanks in advance.