When venting a direct-vent high-efficiency condensing furnace horizontally, how should the vent pipe be pitched?

When venting a direct-vent high-efficiency condensing furnace horizontally, the vent pipe should be pitched toward the furnace. This design ensures that any condensate, which is a byproduct of the combustion process in these high-efficiency systems, can drain back towards the furnace and ultimately into the condensate drain system.

If the vent pipe is not properly pitched towards the furnace, condensate could pool within the vent system, leading to potential blockages, corrosion, or even compromising the operation of the furnace. It's essential to maintain this slope to support proper drainage and ensure the efficiency and safety of the heating system.

Pitched away from the furnace or level positioning can lead to improper drainage and potential operational issues. Therefore, ensuring the correct angle of pitch toward the furnace is critical for maintaining the longevity and efficiency of a high-efficiency condensing furnace.