Red Seal Gasfitter — Class B 2025 – 400 Free Practice Questions to Pass the Exam

Identifying a blocked gas vent can often be accomplished by inspecting for condensation. When a gas vent is blocked, it can lead to a buildup of gases, and as these gases cool, they may cause moisture to condense within the venting system. This condensation can be a clear indicator of an obstruction, as it suggests that the exhaust is not venting properly and is potentially backing up into the system.

In contrast, checking the gas meter reading, looking for air leaks around windows, and monitoring overall gas consumption are not direct indicators of a blocked vent. While changes in gas consumption could imply issues in the system, they do not specifically point to vent blockage. Air leaks around windows are related to building envelope issues and would not provide relevant information about a gas vent's condition. Therefore, inspecting for condensation is the most effective method for determining whether a gas vent is blocked.