Furnace clean and tune. Cycled system. System fired. Checked heat exchanger with camera, found large crack in far left heat exchanger. This is an immediate fail of inspection. System has been disabled until options are given to customer. Black-Haak is not responsible for any injury or other if system is enabled by customer and ran. CO levels may be dispersed into the home causing harm. Black-Haak heating does NOT recommend running heat until system is fixed. Cleaned fireplace. Cycled system. Cleaned glass, walls, logs, igniting system and outside. System operating normal at this time. Job complete. Charges pending results of second opinion.