What is A Backflow Preventer and Why is it Essential to Your Home?

Though it can often go unknown to many homeowners, water backflow has the potential to become quite a serious cause for concern. Many health hazards can spawn from one simple change in how water flows through pipes, increasing the risks of contamination for not only your home but for an entire neighborhood. Fortunately, many homes today are built with backflow preventers to reduce that contamination risk. 

You might be asking yourself questions like, “what is a backflow preventer?” and  “how do they stop such big risks from happening?”. The safety of our families and neighborhood can be important, and ensuring we understand how to prevent backflow can greatly help. We’ve put together this article to answer these questions and why it’s so essential to have one in your home to help. 

If you want to install a new backflow preventer or want to get an existing one serviced, call Diamondback for reliable help today!

What is a Backflow Preventer and How Does it Work?

When water gets pulled into your home’s pipes from the local water supply line, it typically only flows in one direction to the faucets. This is what ensures that whatever water you get is suitable for drinking, cleaning, and bathing. However, some situations can cause said water flow to suddenly reverse, potentially causing soap, waste, and other dangerous contaminants to enter the public water lines.

Fortunately, backflow prevention systems work to prevent this contamination from happening.

Backflow preventers are appliances installed on your home’s main water supply line to keep the incoming water flowing in one direction when properly installed. Turning on a faucet with a backflow preventer in your pipes pulls water through the opened appliance, and turning it off closes the preventer. Much like a one-way gate, no water can go out the same way it came in.

What Causes Backflow in a Pipe?

The most common cause of backflow in your pipes is pressure changes inside the pipes. On occasion, this change can happen due to a fire hydrant getting opened for use nearby and a backflow preventer is the best method of backflow prevention here. However, backflow can also be caused due to breaks in your home’s main water lines. If this is the cause of it, you’ll need to call our team as soon as possible.

The Different Kinds of Backflow

Though the cause is often a change in pressure, backflow can also happen in two different ways. Both back-siphonage and back-pressure can cause different kinds of contamination as well. Though a backflow preventer is the best possible solution, make sure to check the plumbing’s connections as well.


Back-pressure is often caused when the pressure in a non-drinkable water source becomes far greater than the pressure from the water supply pipes. This causes the water, as well as any contaminants, to be pushed back into the water supply and causes contamination. Even something as simple as a higher elevation can cause the water to flow back.

The most common sources of back-pressure are power washing tools, boilers, and even water pumps in a distribution system. The pressure created by these appliances is far stronger than what the water supply line has, causing the flow to reverse.


As the type of backflow that’s often caused by fire hydrants and broken pipes, back-siphonage is caused by a decrease in pressure in the water supply. The drop causes any water that’s still in the pipes to be sucked or siphoned back from the pipe, bringing with it any higher-pressure liquids, solids, or gasses. 

So, what does a backflow preventer do? It helps prevent these kinds of issues, preventing our public water supply from getting contaminated while also preventing sewer wastewater from backing into our homes. A properly placed and installed backflow preventer can be incredibly useful for both our own homes and our neighborhoods.

Backflow Testing and Its Importance for Home Safety

Much like any other plumbing system in your home, a backflow preventer also needs regular maintenance to make sure it keeps working. The quality of your home’s preventer can reveal just how safe your water supply is, especially since some contaminants aren’t as obvious at first. Any appliance or device is capable of wearing down or malfunctioning, and a preventer isn’t any different. 

Calling a plumber to do backflow testing is the best way you can tell whether or not you need to replace it for your home’s safety. Specialized plumbers know exactly how backflow preventers work and have the tools needed for proper testing. With a special testing kit connected, a plumber shut off any water downstream from where the appliance is before checking if any water flows back past it. 

Congratulations! You now know the answer to the question, “how does a backflow preventer work?”.

Do I Need a Preventer for My Home?

As mentioned earlier, many of the homes that have recently been built more than likely have a backflow preventer already installed. However, if you aren’t sure due to the age of your home, you can call our team at Diamondback. 

Depending on where your home is located and what regulations your town or city might have, having a backflow preventer may be a requirement by law. Knowing the answer to the question, “what is a backflow preventer?” and having one installed ensures that not only will your family and neighborhood stay safe but prevents you from facing any potential legal ramifications.

However, if your home draws its water supply from a well or doesn’t have some form of connection to the main water supply, the choice is ultimately up to you as the homeowner. As much as you can choose not to get a backflow preventer installed, having one is still highly recommended, especially when any incoming water is at risk of contamination.


Preventing backflow and backflow preventers themselves are highly crucial safety precautions that all homeowners should at least be aware of. 

Backflow can often carry all sorts of contaminants that can be harmful to your, your family’s, and your neighbors’ health. With how they work, the appliance can stop wastewater from returning to your home or from contaminating the local water supply. 

Regardless, call our team of professional plumbers at Diamondback to schedule your backflow preventer’s maintenance check.

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