What Is Backflow Testing & Why It’s Important? | Roto-Rooter

When pressure changes in your plumbing system reverse the flow of water, pollutants such as fertilizer, sewage, or chemicals can flow backward into your clean water supply. That’s called backflow, and it’s a serious threat to health and safety.

Backflow testing protects your home, business, and community from water contamination by making sure your backflow prevention device is working correctly. Learn more about how to test a backflow preventer to keep your water safe.

What Is a Backflow and How Does It Occur?

Backflow happens when there's a sudden shift in water pressure, usually from a burst pipe, hydrant use, or pump failure. When this occurs, the water in your plumbing system can reverse direction. That means dirty or contaminated water can be pulled into your clean water lines. An example might be chlorine or E. coli bacteria from a swimming pool getting into the water supply and contaminating drinking water.

Common causes include:

Sudden drops in water pressure
Malfunctioning valves or pumps
Improperly installed plumbing connections

Backflow preventers stop toxins from flowing backward into the supply line and endangering public health. Like any plumbing device, they must be maintained and tested regularly.

What Does a Backflow Test Involve?

A backflow test ensures your prevention device is doing its job. During a backflow preventer inspection, a certified backflow tester will:

Shut off the downstream water access
Measure pressure levels before and after the device
Inspect valves and seals
Check for leaks, pressure loss, or mechanical failures

Modern backflow preventer testing uses specialized gauges to evaluate performance. The goal is to confirm that the device can stop contaminated water from entering your supply line.

How to Test a Backflow Preventer

Wondering how to test a backflow prevention device? Professionals follow a step-by-step process:

Turn off the water supply to isolate the device.
Attach a differential pressure gauge to test ports.
Open valves in sequence to check pressure zones.
Record gauge readings to detect any failures.
Submit results to local authorities, if required.

While it may sound straightforward, these tests must be done with care — and usually by a certified professional.

How Much Does Backflow Testing Cost?

Every backflow tester charges a different price. It depends on a few things:

Your location and local regulations
The number of devices being tested
The size and type of your backflow preventer
Whether it's part of a residential or commercial system

In addition to the cost of the test, you may also need to pay a fee to your local municipality to file your paperwork.

Do You Need a Certified Backflow Tester?

In most states and cities, yes. Certified backflow testers are required to hold a license or certification from local water authorities. In addition, you’ll want to find a backflow tester that has ASSE Cross-Connection Control Certification, as this is a nationally recognized certification with rigorous educational requirements.

Choosing a certified plumber, like those at Roto-Rooter, ensures accurate results and peace of mind. Failing to meet inspection standards can lead to fines or unsafe drinking water.

Signs You May Need a Backflow Test or Repair

If your system has any of the following problems, you may need a backflow valve repair soon.

Discolored or foul-smelling tap water
Water that tastes off or metallic
Frequent drops in water pressure
Visible leaks near your backflow preventer

At the first sign of these issues, start looking for a plumber who knows how to repair a backflow valve.

What Is Backflow Repair and When Is It Needed?

Backflow devices can wear out over time. Backflow repair typically involves:

Replacing rubber seals, springs, or check valves
Removing blockages or debris
Rebuilding internal components

If the damage is extensive, you may even need a full backflow valve repair or replacement. When backflow devices fail, repairing them quickly is important if you want to remain compliant and prevent health risks. Luckily, Roto-Rooter is just a call away if you need help. While you may know us for our commercial sewer cleaning, that’s just one of the many services we offer.

Don’t Let Backflow Catch You Off Guard

Backflow testing might not be top of mind, but it’s one of the most important things you can do to protect your property, community, and everyone who uses your water.

Whether you’re a homeowner or a business owner, Roto-Rooter’s certified team can handle your backflow test, repairs, or annual inspections with speed and reliability. Call the Roto-Rooter plumbing professionals today to schedule your appointment.