is recommended that the tobacco pipe be Boiler flue tilted down 5 degrees when installed (1) It can prevent rainwater from flowing back into the machine along the smoke pipe when it rains (2) The exhaust fumes may be slightly downward in case of cold condensation, which is conducive to the elimination of condensation. is recommended that the total length of the tobacco pipe and Aluminum Condensing Flues Suppliers the extension section not exceed 3 meters.