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How To Troubleshoot Your Leaky Backflow Valve

A backflow valve, or backflow preventer, is an important part of your property’s plumbing system. When it’s working correctly, a backflow preventer stops dirty water from mixing with clean drinking water. That’s a critically important mission — and it means that when a backflow preventer is leaking, it can lead to serious issues, like contamination of your drinking water and higher water bills from wasted water. 

With that in mind, you’ll understand why it’s so important to find a reliable plumber with a backflow certification who can help fix your backflow preventer issues. Here, we’ll show you some of the key facts about leaky backflow preventers — and talk about how you can find a solution. 

What Is a Backflow Valve?

A backflow valve or backflow preventer is a series of valves that make sure water flows in only one direction. It prevents contaminated water from flowing backward into a clean water supply, such as a municipal water line. 

In most jurisdictions, backflow preventers are required for businesses and multi-unit buildings, as well as for single-family homes with irrigation systems. Backflow regulations vary from one town or city to another, so it’s always important to check local rules about backflow preventers (and to work with a plumber who’s familiar with them, too). However, most municipalities have strict rules requiring annual inspections of backflow preventers to ensure they are operating properly. Plumbers who are certified in backflow prevention can also take care of your annual inspections and help you submit the required paperwork or online forms.

Signs of a Leaky Backflow Valve

Be on the lookout for these tell-tale signs that your backflow valve is leaking or otherwise malfunctioning:

  • Leaks and Drips: Sometimes, you’ll be able to directly observe water leaking from the valve itself. A small amount of leaking water isn’t a critical concern if it’s coming from the backflow preventer’s relief valve. This can simply mean that the backflow preventer is doing its job and releasing excess pressure or backed-up water. However, persistent flow from the relief valve (or from anywhere else) needs to be investigated.
  • Stains and Rust: If water stains are often visible around your backflow preventer, or you notice rust on its components, it could be a sign of leaks. Check these areas regularly and contact a qualified plumber if there’s a significant amount of rust on your backflow preventer.
  • Water Pressure Spikes or Drops: If you often experience sudden low or high water pressure, check your backflow preventer. Frequent changes in water pressure could indicate that the backflow preventer isn’t handling pressure and flow correctly.
  • Unusual Noises: Hissing, banging, or other strange noises coming from the area of your backflow preventer can be signs of internal issues, such as valves not closing fully or air trapped in the system. 

Don’t Go It Alone

Backflow preventers are somewhat complex and heavily regulated, and trying to fix them yourself could cause more harm than good — even if you consider yourself DIY-savvy. In many places, only licensed plumbers are allowed to work on backflow preventers that connect to a city water supply.

Trained plumbers know how to test your backflow preventer for issues and how to fix a leaking backflow preventer safely. That said, it’s useful for any property owner to know about the common causes of a leaking backflow preventer.

Why Is My Backflow Preventer Leaking?

It’s tricky to determine the cause of a leaky backflow preventer without taking it apart — which, again, is not a job you’ll usually want to do yourself. These are some of the usual suspects: 

Fouled Check Valves

Debris, such as mud and rocks, can become stuck in a backflow preventer’s check valves. This can prevent the valves from closing properly, leading to leaks and compromised system performance.

Worn-Out Components

O-rings, springs, and other components of a backflow preventer can gradually get worn out over time. When these fail, they can cause unpredictable complications with your backflow preventer. 

Incorrect Installation

Sometimes, a backflow preventer has been installed incorrectly, using substandard or mismatched materials or components. If this is the case, a professional may need to rebuild it.

Back Pressure

If your backflow preventer is running often, it might not be a problem with the preventer itself — rather, it could be that the system is experiencing back pressure more often than normal. It’s still worth calling a plumber to investigate since it can point to problems elsewhere in your system.

Whatever is causing your backflow preventer to leak, you need help from a professional plumber to solve it. Fortunately, there’s a Roto-Rooter professional near you who’s waiting for your call. Call our licensed and insured team at 800-768-6911, or schedule your service online any time.



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