One factor that can lead to the early demise of a vacuum breaker (backflow preventer) is leaving the faucet valve open with a hand-held sprayer at the end of the hose used instead to turn the water flow on and aff. Manufacturers do not recommend continuous pressure at the vacuum breaker for more than 12 hours. Behind the ring of tiny holes around the end of the vacuum breaker, where you screw a hose onto it, is a plastic disc that presses up against the holes when the water is turned on, then springs back when pressure drops off, allowing a small amount of air into the faucet head, and continuous pressure leads to early failure. 

    Also, hard water that can encrust the disc with deposits over time is another culprit, or not draining the vacuum breaker before a hard winter freeze (unless it is rated as freeze protected or insulation added around it).

    The solution is pretty simple: replace the vacuum breaker. They unscrew, and there are YouTube videos explaining how to release the set screw and change one out. Replacements cost between $7 and $30, with the upper price range being for freeze-resistant and self-draining models.

    The vacuum breaker  prevents a vacuum from forming due to the loss of water pressure, which could siphon water in the hose back up into the plumbing system. If a hose is submerged a backyard pond or attached to a sprayer with pesticide or fertilizer, the contaminated water could be sucked into the home’s drinking water piping.

    Although this seems like an unlikely occurrence, about two-thirds of all household water contamination events are caused by a backflow siphoning. The gadgets are mandated by the plumbing and building codes and are an important safety device. The problem is they only last about five to ten years before the disc mechanism fails.

    A famous example of backflow water contamination happened during the 1933 Chicago World’s Fair. It killed 98 people and sickened another 1,500, all due a hotel’s faulty plumbing system that allowed back-siphonage of waste water into drinking water and an amoebic dysentery outbreak. Plumbing codes and enforcement for backflow prevention measures were tightened after this tragedy, and it is part of the reason for that little safety device on the end of your hose faucet today.

• • • • • • • • • • • • • • • • • • • • • • • • • • • • • • •

Here’s links to a collection of our other blog posts about PLUMBING PIPES:

• Do I need a vacuum breaker valve for washing machine hose faucets?

• How can I protect my pipes to keep them from bursting during a hard winter freeze in North Florida?

• Can galvanized steel pipe still be used for new water lines in a house? 

• How can I tell if I have cast iron pipes in my house? 

• Why can't a sanitary tee be used for a horizontal-to-horizontal drain pipe connection? 

• What is the difference between green and white sewer drain pipes?

• What is a building trap?  

• What is a galvanized nipple?

• What are the pipes sticking out near my water valves?

• How do you accurately find a broken water pipe leak under the floor slab?

• What is the difference between water pipe and sewage (waste) pipe? 

• How can I find out what type of water pipe runs underground from the water meter to the house (service pipe)?

• What is a P-trap?

• Why is old galvanized steel water pipe a problem for homebuyers?

• What does polybutylene pipe look like? Why is it a problem? 

• Which water pipes are an insurance problem and possibly uninsurable?

• Can you connect CPVC pipe directly to a gas water heater?  

     Visit our PLUMBING page for other related blog posts on this subject, or go to the INDEX for a complete listing of all our articles.