A residence has a closed water supply system because the water meter contains a check valve and a pressure regulator. As the water heater heats water, pressure spikes dangerously. What does the code require to relieve this?

Giải thích

In a closed system, heated water cannot expand back toward the main, so the code requires thermal expansion control such as an expansion tank or approved relief device. Enlarging the main does not absorb expansion, removing the regulator defeats pressure control, and leaving a hose bibb open is not a permanent code-compliant solution.