Core TradesQuestion 143 of 700

The discharge pipe from a water heater's temperature-and-pressure (T&P) relief valve must:

a.Connect directly into the building drainage system
b.Terminate to an approved location near the floor without a threaded end, valve, or cap
c.Be capped when not discharging for safety
d.Discharge into the vent stack

Explanation

The T&P discharge pipe must run downward by gravity to an approved point (typically outside or to a drain with an air gap), terminate 6 to 24 inches above the floor, and have no valve, cap, or threaded end that could be plugged. A direct connection, cap, or vent discharge could trap pressure and cause the tank to burst.

Law Reference: 2025 CA Plumbing Code §608.0

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