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Do I Really Need a Backflow Preventer?

Nov 16, 2020

Person washing their hands under running water in a kitchen sink.

Your home’s plumbing is a complicated system of various necessary components, including pipes, valves, pumps, and a backflow preventer.


But what is a backflow preventer and how do backflow preventers work? What happens if your backflow preventer is out of date, or if your home’s plumbing system lacks one entirely? This article will answer all these questions and more.

What is a Backflow Preventer?

A backflow preventer is an appliance installed on your main water supply pipes to keep water continuously moving in one direction, which helps prevent contaminants from backflowing into your clean water supply. 


When water enters your home via the main water supply line, it should only ever flow in one direction: inwards. This ensures that the water is safe for drinking, bathing, washing, and any other home needs. However, due to pressure changes that can occur in pipes, water can sometimes flow backwards, seeping back into the main water supply line if not stopped. Situations like these can occur if there has been any breakage in the main water supply line, if a fire hydrant is opened for use, or any other time when there’s been significant pressure change. 


If a major pressure change occurs and homes are not equipped with backflow preventers, water can flush backwards into municipal water lines, potentially contaminating the water with soap from sinks or dishwashers, human waste from toilets, chlorine from pools, fertilizers, pesticides, and any number of other dangerous contaminants.

How Do Backflow Preventers Work?

When properly installed, a backflow preventer works by only allowing water to flow in one direction in a pipe. In a way, a backflow preventer works like a one-way gate. It opens in one direction, thereby allowing clean water to flow into your main water supply line, but closes to any water flowing in the opposite direction, preventing any backflow. 


If you ever find your backflow preventer isn’t working, or your home doesn’t have a backflow preventer at all and contaminated water has made its way to your showers and sinks, stop using the water and contact your plumber right away. Contaminated water due to backflow in your water supply line is an emergency plumbing situation and should be addressed immediately.

Do I Really Need a Backflow Preventer?

Depending on your home’s location and the regulations where you live, you may be required to have a backflow preventer installed on your water line to protect yourself and your town or city from the risk of water contamination.


In homes without an irrigation system or that run on a well, it can be up to the homeowner to decide whether or not to install a backflow preventer. Understand that it is always recommended to install a backflow preventer in any situation where incoming water and waste water have a chance of being cross-connected. This serves to protect you and your home, keeping your drinking, bathing, and cleaning water safe.

The Importance of Backflow Tests

Many homes today are built with a backflow preventer already installed, but if you’re not sure if your home has one, consider having a licensed plumber come out to inspect your unit and install a backflow preventer if needed.


Additionally, even if your home does have a backflow preventer, it’s important to get your preventer tested regularly to ensure your water is safe for daily use. Since any device is capable of malfunctioning, backflow testing is key to helping you keep your water supply clean. A proper backflow test can identify if any contaminated water may have made its way back into your water supply.


A good rule of thumb is to get your backflow preventer tested yearly to ensure the device is working correctly. The test is fairly simple for a professional plumber to fulfill. After connecting a testing kit to the backflow preventer, they will shut off any water downstream from the device and check to see that the backflow preventer is working correctly.

Work with the DMV’s Trusted Backflow Professionals

Backflow prevention is an important safety measure all homeowners should be aware of. Our 5-Star plumbing technicians have all of the skills and tools to protect your family and home from backflow emergencies. Check out our full list of service areas, and for more information about one of Virginia’s most trusted names in plumbing service and repair, call CroppMetcalfe at 877-740-6657 or contact us online to schedule an appointment today.


What Our Customers Say...

"I've been a CroppMetcalfe customer for 9 years and you have always provided outstanding service. I just had my semi-annual maintenance done, and I wanted to thank George for the truly outstanding service, professionalism, and excellent advice. He is definitely one of the best 5-Star Technicians I've had! Thank you CroppMetcalfe!"

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