Core TradesQuestion 32 of 700
A backwater valve on a building drain is required PRIMARILY where:
a.A fixture is on the top floor of a multi-story building
b.Fixtures are located below the level of the next upstream sewer manhole cover
c.The building has more than one cleanout
d.The water heater lacks a T&P relief valve
Explanation
A backwater valve protects low fixtures that sit below the upstream manhole rim by preventing sewage from backing up into them during a surcharge. Top-floor fixtures, cleanout count, and water-heater valves are unrelated to this requirement.
Law Reference: 2025 CA Plumbing Code (CPC) §710 (Backwater Valves)Practice all 700 questions free — no signup required.
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