This is an estimate for replacing the heat exchanger assembly. Upon inspection, it was determined that the current heat exchanger was malfunctioning, leading to inefficient heating. The replacement involves removing the old heat exchanger, installing the new one, and ensuring all connections are secure and safe. This process requires specialized tools and knowledge to ensure proper installation. The new part is in stock and ready for immediate installation. This estimate includes both labor and materials. If you approve, we will schedule the replacement for tomorrow. Thank you.