Can I leave my non-freeze wall hydrant under continuous water pressure?

No, the American Society of Sanitary Engineering states that all Non-Freeze Wall Hydrant installation instructions shall have the following warning “this ASSE 1019 device shall not be subjected to more than twelve (12) hours of continuous water pressure.”

See section 4.3-1 copied below.

Leaving your hose bibb or frost-proof wall hydrant open for extended periods is not only against the “ASSE 1019-2011 - Wall Hydrant with Backflow Protection and Freeze Resistance” certification for back-flow prevention, but the constant pressure, even if the water is not flowing, will cause damage to the back-flow prevention check valve.

Therefore, Boshart like all other brands, does not recommend leaving the hydrant under constant pressure, this would be the situation if you were to install a hose timer. Non-Freeze Wall hydrants with an anti-siphon protection are great for irrigation purposes. However, timers require you to leave your hose bibb or wall hydrant turned on with continuous pressure for long periods of time.