What is a common plumbing code requirement regarding water supply connections for water heaters?

A common plumbing code requirement regarding water supply connections for water heaters is that full-open valves must be installed. This requirement ensures that the water supply to the water heater can be easily turned off in case of an emergency or for maintenance purposes. Full-open valves allow for unrestricted water flow when they are in the open position, facilitating both effective operation and serviceability of the water heater system.

The requirement for full-open valves enhances safety by enabling quick access to shut off water supply, reducing the risk of leaks or flooding in the event of a failure in the water heater system. This practice aligns with established plumbing codes that prioritize both function and safety in residential and commercial plumbing installations.