The disc is doing its job, saving your life! If the heat exchanger gets too hot this disc is the safety. Find out how hot the heat exchanger is getting and what the disc is rated for. Check that there is air flowing over the heat exchanger keeping it from over heating. If your vent was installed incorrectly it could be keeping too much heat inside the furnace not allowing it to escape to the outside.
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The disc is doing its job, saving your life! If the heat exchanger gets too hot this disc is the safety. Find out how hot the heat exchanger is getting and what the disc is rated for. Check that there is air flowing over the heat exchanger keeping it from over heating. If your vent was installed incorrectly it could be keeping too much heat inside the furnace not allowing it to escape to the outside.