Red Seal Gasfitter — Class A Practice Exam

When installing a gas hot water heater, what should be ensured regarding the vent?

1. It must be installed at ground level

2. It does not require a vent

3. It must be properly sized and installed to prevent flue gas exposure

4. It should be located near the gas meter

The correct answer is: It must be properly sized and installed to prevent flue gas exposure

When installing a gas hot water heater, ensuring that the vent is properly sized and installed to prevent flue gas exposure is crucial for several reasons. Proper venting is essential to safely remove combustion gases from the appliance to the outdoors, thereby protecting the health and safety of occupants. If the vent is undersized, it could lead to backdrafting, where flue gases are drawn back into the living space instead of being expelled outside, potentially causing carbon monoxide buildup and other hazardous situations. Moreover, the venting system must be correctly installed to maintain the necessary draft that supports efficient combustion and minimizes the risk of flue gas leaks. Compliance with local building codes and manufacturers' specifications for venting is also critical to ensure safe operation of the gas hot water heater. Other choices do not promote safe practices. For example, suggesting that the vent should be installed at ground level eliminates proper gas removal and could lead to dangerous conditions. Stating that the appliance does not require a vent is misleading since all gas appliances must vent exhaust gases to avoid the risk of harm. Lastly, while the vent could be near a gas meter, it is not a requirement, and this does not address the vital issue of safe exhaust gas management.