Fully premixed low nitrogen condensing gas boiler, also known as a fully premixed condensing gas module furnace, features completely independent modules that serve as backups for each other, enabling true online maintenance and repair without downtime. The fully premixed low nitrogen condensing gas module furnace utilizes full premixed condensing combustion technology. This technology involves the complete pre-mixing of air and gas in a specific ratio before entering the combustion chamber, resulting in instant combustion. The flame is short and the heat intensity at the flame holes is high, allowing for more complete combustion without the need for additional air during the process. Consequently, there is less heat loss and reduced emissions of harmful gases, making it a relatively forward-looking combustion technology internationally.