CSLB C-36 Plumbing ContractorRough-in PlumbingMedium
A plumbing contractor is installing a new water heater in a residential garage. The water heater is gas-fired. What is the minimum required height above the igniter for the vent termination, measured from the highest point where the vent passes through the roof?
- A12 inches
- B6 inches
- C24 inches
- D18 inches
Show answer & explanationAnswer & explanation
Correct answer: A. 12 inches
According to the California Plumbing Code (CPC), the vent for a gas appliance must terminate at least 12 inches above the highest point where it passes through the roof to ensure proper draft and dispersion of combustion byproducts.
Why the other options are wrong
- B. 6 inches is generally insufficient for proper draft and clearance, and does not meet CPC requirements.
- C. 24 inches provides good clearance but is more than the minimum required by code.
- D. 18 inches is a common clearance but not the minimum for this specific scenario.
Gas Vent Termination
The final outlet of a gas appliance vent pipe, designed to safely discharge combustion byproducts to the outside atmosphere.
- Ensures safe operation of gas appliances.
- Prevents carbon monoxide buildup.
- Code-mandated clearances from roof and other obstructions.
Memory trick: Vent high and clear, so fumes disappear, 12 inches from the roof, have no fear.