Tech completed diagnostic at indoor furnace system only. Tech noticed gas line a connection are good. But furnace heat exchanger is bad with potential cracks at heat exchanger, this can lead to a fire hazard in buildings when furnace is being operated in heat mode… tech also found other issues and concerns at furnace that also need addressing.. Please review email, to respond to any estimates you can do so by email or calling in to reschedule appointments. *Thanks for choosing TE Certified if you liked your technician service today don’t hesitate to leave a 5 star review!