Sprinkler System Vacuum Breaker Valve

Knowing sprinklers systems are not part of our SOP …

One of my neighbors had a automatic sprinkler system installed at her home last fall. After having a pipe burst last winter at the vacuum breaker, and extremely high water bills this summer, she asked if I would take a look at it. The system is tied both to city water and to a private well. City water side runs directly from the city water meter to the atmospheric vacuum breaker shut off valve at the front exterior of the house then ties in to the well pump output lines in the crawl space and to the sprinkler system zone control valves.

There is no way to winterize the sprinkler riser tree (vacuum breaker / valves) without shutting of the city water to the house.

I have noted repeatedly in homes that I have inspected a shut off valve for the sprinkler system installed inside the house down stream from the main shut off valve.


  1. Should sprinkler system be tied directly to city water system
  2. Should sprinkler system be isolated via valve after the house main water shut off valve
  3. Is there a standard / code that provides detail

your help would be appriciated…

So long as there is a vacuum-break or anti-siphon valve, it’s OK.

“Best practices” would dictate so.

UPC 603.4.6 through 603.4.6.4 and IRC 2902.4.3

Jeff’s right. The NFPA is G_D for all fire suppression systems. Why would the water bill be high unless sprinkler is going off or she is trying to fill the well.

Fire suppression systems are a completely separate issue. In CA, most of these systems are under control of the local fire department/authority and cannot be modified without the appropriate permission.

My assumption was that we were referring to irrigation sprinklers. . .


Thanks for the response, it is an irrigation system. They have it tied to both a well and to city water ??? We are trying to find out why at this time. Friend remembers the well company saying they were not getting enough volume / pressure from the well and that they needed to drill a second well, next thing she knew, they were gone and the sprinkler system was working. …

Looks like they desided to hook into the city water system to supplement the system. Sprinkler company and well company area supposed to come out next week to point fingers at each other.

Sorry about that.