? Is there a thermostat to
kick the burners off in the event the heat exchanger reaches a critical
temperature in case something like this happens? Thanks for any
replies...Jim
Some hot air furnaces use a air flow switch for this. It is a switch
mounted on the air plenum with a little flat piece of metal inside the
plenum.

Thanks to all that replied...It sets my mind at ease knowing that there is
something to prevent that from happening....have a good week...Jim