When is it appropriate to connect a water heater using a flexible connector?

The idea of connecting a water heater using a flexible connector is primarily guided by safety and code regulations. Flexible connectors can be beneficial in certain scenarios, particularly when they allow for easier installation and maintenance due to the ability to absorb movement and mitigate stress on piping.

The correct answer encompasses various contexts where connecting a water heater with a flexible connector may be deemed permissible, such as during the replacement of an existing heater or during the installation of a new one, especially when space constraints come into play.

In practice, flexible connectors may be used appropriately when replacing a water heater, as they facilitate a smoother transition from the old system to the new one. Additionally, they can be particularly helpful when the new heater's location requires a bit more adaptability due to space considerations.

Therefore, it can be stated that while flexible connectors might seem appealing in a variety of applications, the overall code might dictate specific circumstances where they're allowed, typically under certain conditions such as during installation or replacement, when deemed safe and effective in aligning with plumbing principles.